Chapter 17 - Galapagos Archipelago
SEPTEMBER 15th. -- This archipelago consists of tenprincipal islands, of which five exceed the others insize. They are situated under the Equator, and betweenfive and six hundred miles westward of the coast ofAmerica. They are all formed of volcanic rocks; a fewfragments of granite curiously glazed and altered by theheat, can hardly be considered as an exception. Some ofthe craters, surmounting the larger islands, are of immensesize, and they rise to a height of between three and fourthousand feet. Their flanks are studded by innumerablesmaller orifices. I scarcely hesitate to affirm, that theremust be in the whole archipelago at least two thousandcraters. These consist either of lava or scoriae, or of finely-stratified, sandstone-like tuff. Most of the latter arebeautifully symmetrical; they owe their origin to eruptions ofvolcanic mud without any lava: it is a remarkable circumstancethat every one of the twenty-eight tuff-craters whichwere examined, had their southern sides either much lowerthan the other sides, or quite broken down and removed. Asall these craters apparently have been formed when standingin the sea, and as the waves from the trade wind and theswell from the open Pacific here unite their forces on thesouthern coasts of all the islands, this singular uniformityin the broken state of the craters, composed of the soft andyielding tuff, is easily explained.
Considering that these islands are placed directly underthe equator, the climate is far from being excessively hot;this seems chiefly caused by the singularly low temperatureof the surrounding water, brought here by the great southern
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Polar current. Excepting during one short season, verylittle rain falls, and even then it is irregular; but the cloudsgenerally hang low. Hence, whilst the lower parts of theislands are very sterile, the upper parts, at a height of athousand feet and upwards, possess a damp climate and atolerably luxuriant vegetation. This is especially the caseon the windward sides of the islands, which first receive andcondense the moisture from the atmosphere.
In the morning (17th) we landed on Chatham Island,which, like the others, rises with a tame and rounded outline,broken here and there by scattered hillocks, the remainsof former craters. Nothing could be less inviting than thefirst appearance. A broken field of black basaltic lava,thrown into the most rugged waves, and crossed by greatfissures, is everywhere covered by stunted, sun-burnt brushwood,which shows little signs of life. The dry and parchedsurface, being heated by the noon-day sun, gave to the aira close and sultry feeling, like that from a stove: we fanciedeven that the bushes smelt unpleasantly. Although I diligentlytried to collect as many plants as possible, I succeededin getting very few; and such wretched-looking littleweeds would have better become an arctic than an equatorialFlora. The brushwood appears, from a short distance, asleafless as our trees during winter; and it was some timebefore I discovered that not only almost every plant wasnow in full leaf, but that the greater number were in flower.The commonest bush is one of the Euphorbiaceae: an acaciaand a great odd-looking cactus are the only trees whichafford any shade. After the season of heavy rains, the islandsare said to appear for a short time partially green. Thevolcanic island of Fernando Noronha, placed in many respectsunder nearly similar conditions, is the only othercountry where I have seen a vegetation at all like this ofthe Galapagos Islands.
The Beagle sailed round Chatham Island, and anchoredin several bays. One night I slept on shore on a part of theisland, where black truncated cones were extraordinarilynumerous: from one small eminence I counted sixty ofthem, all surmounted by craters more or less perfect. Thegreater number consisted merely of a ring of red scoriaeor slags, cemented together: and their height above the plainof lava was not more than from fifty to a hundred feet; nonehad been very lately active. The entire surface of this partof the island seems to have been permeated, like a sieve, bythe subterranean vapours: here and there the lava, whilstsoft, has been blown into great bubbles; and in other parts,the tops of caverns similarly formed have fallen in, leavingcircular pits with steep sides. From the regular form of themany craters, they gave to the country an artificial appearance,which vividly reminded me of those parts of Staffordshire,where the great iron-foundries are most numerous.The day was glowing hot, and the scrambling over the roughsurface and through the intricate thickets, was very fatiguing;but I was well repaid by the strange Cyclopean scene.As I was walking along I met two large tortoises, each ofwhich must have weighed at least two hundred pounds: onewas eating a piece of cactus, and as I approached, it staredat me and slowly walked away; the other gave a deep hiss,and drew in its head. These huge reptiles, surrounded bythe black lava, the leafless shrubs, and large cacti, seemed tomy fancy like some antediluvian animals. The few dull-coloured birds cared no more for me than they did for thegreat tortoises.
23rd. -- The Beagle proceeded to Charles Island. Thisarchipelago has long been frequented, first by the bucaniers,and latterly by whalers, but it is only within the last sixyears, that a small colony has been established here. Theinhabitants are between two and three hundred in number;they are nearly all people of colour, who have been banishedfor political crimes from the Republic of the Equator, ofwhich Quito is the capital. The settlement is placed aboutfour and a half miles inland, and at a height probably of athousand feet. In the first part of the road we passedthrough leafless thickets, as in Chatham Island. Higher up,the woods gradually became greener; and as soon as wecrossed the ridge of the island, we were cooled by a finesoutherly breeze, and our sight refreshed by a green andthriving vegetation. In this upper region coarse grasses andferns abound; but there are no tree-ferns: I saw nowhereany member of the palm family, which is the more singular,as 360 miles northward, Cocos Island takes its name fromthe number of cocoa-nuts. The houses are irregularly scatteredover a flat space of ground, which is cultivated withsweet potatoes and bananas. It will not easily be imaginedhow pleasant the sight of black mud was to us, after havingbeen so long, accustomed to the parched soil of Peru andnorthern Chile. The inhabitants, although complaining ofpoverty, obtain, without much trouble, the means of subsistence.In the woods there are many wild pigs and goats;but the staple article of animal food is supplied by thetortoises. Their numbers have of course been greatly reducedin this island, but the people yet count on two days'hunting giving them food for the rest of the week. It issaid that formerly single vessels have taken away as manyas seven hundred, and that the ship's company of a frigatesome years since brought down in one day two hundredtortoises to the beach.
September 29th. -- We doubled the south-west extremity ofAlbemarle Island, and the next day were nearly becalmedbetween it and Narborough Island. Both are covered withimmense deluges of black naked lava, which have flowed eitherover the rims of the great caldrons, like pitch over therim of a pot in which it has been boiled, or have burst forthfrom smaller orifices on the flanks; in their descent theyhave spread over miles of the sea-coast. On both of theseislands, eruptions are known to have taken place; and inAlbemarle, we saw a small jet of smoke curling from thesummit of one of the great craters. In the evening weanchored in Bank's Cove, in Albemarle Island. The nextmorning I went out walking. To the south of the brokentuff-crater, in which the Beagle was anchored, there wasanother beautifully symmetrical one of an elliptic form; itslonger axis was a little less than a mile, and its depth about500 feet. At its bottom there was a shallow lake, in themiddle of which a tiny crater formed an islet. The day wasoverpoweringly hot, and the lake looked clear and blue: Ihurried down the cindery slope, and, choked with dust,eagerly tasted the water -- but, to my sorrow, I found it saltas brine.
The rocks on the coast abounded with great black lizards,between three and four feet long; and on the hills, an uglyyellowish-brown species was equally common. We saw many of thislatter kind, some clumsily running out of the way, and othersshuffling into their burrows. I shall presently describe inmore detail the habits of both these reptiles. The whole ofthis northern part of Albemarle Island is miserably sterile.
October 8th. -- We arrived at James Island: this island, aswell as Charles Island, were long since thus named after ourkings of the Stuart line. Mr. Bynoe, myself, and our servantswere left here for a week, with provisions and a tent,whilst the Beagle went for water. We found here a partyof Spaniards, who had been sent from Charles Island to dryfish, and to salt tortoise-meat. About six miles inland, andat the height of nearly 2000 feet, a hovel had been built inwhich two men lived, who were employed in catching tortoises,whilst the others were fishing on the coast. I paidthis party two visits, and slept there one night. As in theother islands, the lower region was covered by nearly leaflessbushes, but the trees were here of a larger growth thanelsewhere, several being two feet and some even two feet nineinches in diameter. The upper region being kept damp bythe clouds, supports a green and flourishing vegetation. Sodamp was the ground, that there were large beds of a coarsecyperus, in which great numbers of a very small water-raillived and bred. While staying in this upper region, we livedentirely upon tortoise-meat: the breast-plate roasted (as theGauchos do _carne con cuero_), with the flesh on it, is verygood; and the young tortoises make excellent soup; butotherwise the meat to my taste is indifferent.
One day we accompanied a party of the Spaniards intheir whale-boat to a salina, or lake from which salt isprocured. After landing, we had a very rough walk over arugged field of recent lava, which has almost surrounded atuff-crater, at the bottom of which the salt-lake lies. Thewater is only three or four inches deep, and rests on a layerof beautifully crystallized, white salt. The lake is quitecircular, and is fringed with a border of bright green succulentplants; the almost precipitous walls of the crater are clothedwith wood, so that the scene was altogether both picturesqueand curious. A few years since, the sailors belonging to asealing-vessel murdered their captain in this quiet spot; andwe saw his skull lying among the bushes.
During the greater part of our stay of a week, the skywas cloudless, and if the trade-wind failed for an hour, theheat became very oppressive. On two days, the thermometerwithin the tent stood for some hours at 93 degs.; but in the openair, in the wind and sun, at only 85 degs. The sand was extremelyhot; the thermometer placed in some of a brown colourimmediately rose to 137 degs., and how much above thatit would have risen, I do not know, for it was not graduatedany higher. The black sand felt much hotter, so thateven in thick boots it was quite disagreeable to walk over it.
The natural history of these islands is eminently curious,and well deserves attention. Most of the organic productionsare aboriginal creations, found nowhere else; there is evena difference between the inhabitants of the different islands;yet all show a marked relationship with those of America,though separated from that continent by an open space ofocean, between 500 and 600 miles in width. The archipelagois a little world within itself, or rather a satellite attachedto America, whence it has derived a few stray colonists, andhas received the general character of its indigenousproductions. Considering the small size of the islands, we feelthe more astonished at the number of their aboriginal beings,and at their confined range. Seeing every height crownedwith its crater, and the boundaries of most of the lava-streams still distinct, we are led to believe that within aperiod geologically recent the unbroken ocean was herespread out. Hence, both in space and time, we seem to bebrought somewhat near to that great fact -- that mystery ofmysteries -- the first appearance of new beings on this earth.
Of terrestrial mammals, there is only one which must beconsidered as indigenous, namely, a mouse (Mus Galapagoensis),and this is confined, as far as I could ascertain, toChatham Island, the most easterly island of the group. Itbelongs, as I am informed by Mr. Waterhouse, to a divisionof the family of mice characteristic of America. At JamesIsland, there is a rat sufficiently distinct from the commonkind to have been named and described by Mr. Waterhouse;but as it belongs to the old-world division of the family, andas this island has been frequented by ships for the last hundredand fifty years, I can hardly doubt that this rat ismerely a variety produced by the new and peculiar climate,food, and soil, to which it has been subjected. Although noone has a right to speculate without distinct facts, yet evenwith respect to the Chatham Island mouse, it should be bornein mind, that it may possibly be an American species importedhere; for I have seen, in a most unfrequented part ofthe Pampas, a native mouse living in the roof of a newlybuilt hovel, and therefore its transportation in a vessel isnot improbable: analogous facts have been observed by Dr.Richardson in North America.
Of land-birds I obtained twenty-six kinds, all peculiar tothe group and found nowhere else, with the exception of onelark-like finch from North America (Dolichonyx oryzivorus),which ranges on that continent as far north as 54 degs., andgenerally frequents marshes. The other twenty-five birdsconsist, firstly, of a hawk, curiously intermediate in structurebetween a buzzard and the American group of carrion-feedingPolybori; and with these latter birds it agrees mostclosely in every habit and even tone of voice. Secondly,there are two owls, representing the short-eared and whitebarn-owls of Europe. Thirdly, a wren, three tyrant-flycatchers(two of them species of Pyrocephalus, one or both ofwhich would be ranked by some ornithologists as only varieties),and a dove -- all analogous to, but distinct from, Americanspecies. Fourthly, a swallow, which though differingfrom the Progne purpurea of both Americas, only in beingrather duller colored, smaller, and slenderer, is consideredby Mr. Gould as specifically distinct. Fifthly, there are threespecies of mocking thrush -- a form highly characteristic ofAmerica. The remaining land-birds form a most singulargroup of finches, related to each other in the structure oftheir beaks, short tails, form of body and plumage: there arethirteen species, which Mr. Gould has divided into foursubgroups. All these species are peculiar to this archipelago;and so is the whole group, with the exception of one speciesof the sub-group Cactornis, lately brought from Bow Island,in the Low Archipelago. Of Cactornis, the two species maybe often seen climbing about the flowers of the great cactus-trees; but all the other species of this group of finches,mingled together in flocks, feed on the dry and sterile groundof the lower districts. The males of all, or certainly of thegreater number, are jet black; and the females (with perhapsone or two exceptions) are brown. The most curious fact isthe perfect gradation in the size of the beaks in the differentspecies of Geospiza, from one as large as that of a hawfinchto that of a chaffinch, and (if Mr. Gould is right in includinghis sub-group, Certhidea, in the main group) even tothat of a warbler. The largest beak in the genus Geospizais shown in Fig. 1, and the smallest in Fig. 3; but instead ofthere being only one intermediate species, with a beak ofthe size shown in Fig. 2, there are no less than six specieswith insensibly graduated beaks. The beak of the sub-groupCerthidea, is shown in Fig. 4. The beak of Cactornis is
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1. Geospiza magnirostris. 2. Geospiza fortis.3. Geospiza parvula. 4. Certhidea olivasea.
somewhat like that of a starling, and that of the fourthsubgroup, Camarhynchus, is slightly parrot-shaped. Seeing thisgradation and diversity of structure in one small, intimatelyrelated group of birds, one might really fancy that from anoriginal paucity of birds in this archipelago, one species hadbeen taken and modified for different ends. In a like mannerit might be fancied that a bird originally a buzzard, had beeninduced here to undertake the office of the carrion-feedingPolybori of the American continent.
Of waders and water-birds I was able to get only elevenkinds, and of these only three (including a rail confined tothe damp summits of the islands) are new species. Consideringthe wandering habits of the gulls, I was surprised tofind that the species inhabiting these islands is peculiar, butallied to one from the southern parts of South America.The far greater peculiarity of the land-birds, namely,twenty-five out of twenty-six, being new species, or at leastnew races, compared with the waders and web-footed birds, isin accordance with the greater range which these latterorders have in all parts of the world. We shall hereaftersee this law of aquatic forms, whether marine or freshwater,being less peculiar at any given point of the earth'ssurface than the terrestrial forms of the same classes,strikingly illustrated in the shells, and in a lesser degree inthe insects of this archipelago.
Two of the waders are rather smaller than the same speciesbrought from other places: the swallow is also smaller,though it is doubtful whether or not it is distinct from itsanalogue. The two owls, the two tyrant-catchers (Pyrocephalus)and the dove, are also smaller than the analogousbut distinct species, to which they are most nearly related;on the other hand, the gull is rather larger. The two owls,the swallow, all three species of mocking-thrush, the dovein its separate colours though not in its whole plumage, theTotanus, and the gull, are likewise duskier coloured thantheir analogous species; and in the case of the mocking-thrush and Totanus, than any other species of the two genera.With the exception of a wren with a fine yellow breast,and of a tyrant-flycatcher with a scarlet tuft and breast, noneof the birds are brilliantly coloured, as might have beenexpected in an equatorial district. Hence it would appearprobable, that the same causes which here make the immigrantsof some peculiar species smaller, make most of thepeculiar Galapageian species also smaller, as well as verygenerally more dusky coloured. All the plants have awretched, weedy appearance, and I did not see one beautifulflower. The insects, again, are small-sized and dull-coloured,and, as Mr. Waterhouse informs me, there is nothing in theirgeneral appearance which would have led him to imaginethat they had come from under the equator.
We will now turn to the order of reptiles, which givesthe most striking character to the zoology of these islands.The species are not numerous, but the numbers of individualsof each species are extraordinarily great. There is onesmall lizard belonging to a South American genus, and twospecies (and probably more) of the Amblyrhynchus -- a genusconfined to the Galapagos Islands. There is one snake whichis numerous; it is identical, as I am informed by M. Bibron,with the Psammophis Temminckii from Chile.
I will first describe the habits of the tortoise (Testudonigra, formerly called Indica), which has been so frequentlyalluded to. These animals are found, I believe, on all theislands of the archipelago; certainly on the greater number.They frequent in preference the high damp parts, but theylikewise live in the lower and arid districts. I have alreadyshown, from the numbers which have been caught in a singleday, how very numerous they must be. Some grow to animmense size: Mr. Lawson, an Englishman, and vice-governorof the colony, told us that he had seen several so large,that it required six or eight men to lift them from theground; and that some had afforded as much as two hundredpounds of meat. The old males are the largest, the femalesrarely growing to so great a size: the male can readily bedistinguished from the female by the greater length of itstail. The tortoises which live on those islands where thereis no water, or in the lower and arid parts of the others, feedchiefly on the succulent cactus. Those which frequent thehigher and damp regions, eat the leaves of various trees, akind of berry (called guayavita) which is acid and austere,and likewise a pale green filamentous lichen (Usnera plicata),that hangs from the boughs of the trees.
The tortoise is very fond of water, drinking large quantities,and wallowing in the mud. The larger islands alonepossess springs, and these are always situated towards thecentral parts, and at a considerable height. The tortoises,therefore, which frequent the lower districts, when thirsty,are obliged to travel from a long distance. Hence broad andwell-beaten paths branch off in every direction from thewells down to the sea-coast; and the Spaniards by followingthem up, first discovered the watering-places. When I landedat Chatham Island, I could not imagine what animal travelledso methodically along well-chosen tracks. Near the springsit was a curious spectacle to behold many of these hugecreatures, one set eagerly travelling onwards with outstretchednecks, and another set returning, after havingdrunk their fill. When the tortoise arrives at the spring,quite regardless of any spectator, he buries his head in thewater above his eyes, and greedily swallows great mouthfuls,at the rate of about ten in a minute. The inhabitants sayeach animal stays three or four days in the neighbourhoodof the water, and then returns to the lower country; butthey differed respecting the frequency of these visits. Theanimal probably regulates them according to the nature ofthe food on which it has lived. It is, however, certain, thattortoises can subsist even on these islands where there is noother water than what falls during a few rainy days in theyear.
I believe it is well ascertained, that the bladder of the frogacts as a reservoir for the moisture necessary to its existence:such seems to be the case with the tortoise. For sometime after a visit to the springs, their urinary bladders aredistended with fluid, which is said gradually to decrease involume, and to become less pure. The inhabitants, whenwalking in the lower district, and overcome with thirst, oftentake advantage of this circumstance, and drink the contentsof the bladder if full: in one I saw killed, the fluid was quitelimpid, and had only a very slightly bitter taste. Theinhabitants, however, always first drink the water in thepericardium, which is described as being best.
The tortoises, when purposely moving towards any point,travel by night and day, and arrive at their journey's endmuch sooner than would be expected. The inhabitants, fromobserving marked individuals, consider that they travel adistance of about eight miles in two or three days. One largetortoise, which I watched, walked at the rate of sixty yardsin ten minutes, that is 360 yards in the hour, or four miles aday, -- allowing a little time for it to eat on the road. Duringthe breeding season, when the male and female are together,the male utters a hoarse roar or bellowing, which, it is said,can be heard at the distance of more than a hundred yards.The female never uses her voice, and the male only at thesetimes; so that when the people hear this noise, they knowthat the two are together. They were at this time (October)laying their eggs. The female, where the soil is sandy, depositsthem together, and covers them up with sand; butwhere the ground is rocky she drops them indiscriminatelyin any hole: Mr. Bynoe found seven placed in a fissure. Theegg is white and spherical; one which I measured was seveninches and three-eighths in circumference, and thereforelarger than a hen's egg. The young tortoises, as soon as theyare hatched, fall a prey in great numbers to the carrion-feeding buzzard. The old ones seem generally to die fromaccidents, as from falling down precipices: at least, severalof the inhabitants told me, that they never found one deadwithout some evident cause.
The inhabitants believe that these animals are absolutelydeaf; certainly they do not overhear a person walking closebehind them. I was always amused when overtaking one ofthese great monsters, as it was quietly pacing along, to seehow suddenly, the instant I passed, it would draw in its headand legs, and uttering a deep hiss fall to the ground with aheavy sound, as if struck dead. I frequently got on theirbacks, and then giving a few raps on the hinder part of theirshells, they would rise up and walk away; -- but I found itvery difficult to keep my balance. The flesh of this animal islargely employed, both fresh and salted; and a beautifullyclear oil is prepared from the fat. When a tortoise is caught,the man makes a slit in the skin near its tail, so as to seeinside its body, whether the fat under the dorsal plate isthick. If it is not, the animal is liberated and it is said torecover soon from this strange operation. In order to securethe tortoise, it is not sufficient to turn them like turtle, forthey are often able to get on their legs again.
There can be little doubt that this tortoise is an aboriginalinhabitant of the Galapagos; for it is found on all, or nearlyall, the islands, even on some of the smaller ones where thereis no water; had it been an imported species, this wouldhardly have been the case in a group which has been so littlefrequented. Moreover, the old Bucaniers found this tortoisein greater numbers even than at present: Wood and Rogersalso, in 1708, say that it is the opinion of the Spaniards, thatit is found nowhere else in this quarter of the world. It isnow widely distributed; but it may be questioned whetherit is in any other place an aboriginal. The bones of a tortoiseat Mauritius, associated with those of the extinct Dodo,have generally been considered as belonging to this tortoise;if this had been so, undoubtedly it must have been thereindigenous; but M. Bibron informs me that he believes thatit was distinct, as the species now living there certainly is.
The Amblyrhynchus, a remarkable genus of lizards, is confinedto this archipelago; there are two species, resembling
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each other in general form, one being terrestrial and theother aquatic. This latter species (A. cristatus) was firstcharacterized by Mr. Bell, who well foresaw, from its short,broad head, and strong claws of equal length, that its habitsof life would turn out very peculiar, and different from thoseof its nearest ally, the Iguana. It is extremely common on allthe islands throughout the group, and lives exclusively on therocky sea-beaches, being never found, at least I never sawone, even ten yards in-shore. It is a hideous-looking creature,of a dirty black colour, stupid, and sluggish in its movements.The usual length of a full-grown one is about a yard,but there are some even four feet long; a large one weighedtwenty pounds: on the island of Albemarle they seem togrow to a greater size than elsewhere. Their tails are flattenedsideways, and all four feet partially webbed. They areoccasionally seen some hundred yards from the shore,swimming about; and Captain Collnett, in his Voyage says,"They go to sea in herds a-fishing, and sun themselves onthe rocks; and may be called alligators in miniature." Itmust not, however, be supposed that they live on fish. Whenin the water this lizard swims with perfect ease and quickness,by a serpentine movement of its body and flattened tail-- the legs being motionless and closely collapsed on its sides.A seaman on board sank one, with a heavy weight attachedto it, thinking thus to kill it directly; but when, an hourafterwards, he drew up the line, it was quite active. Theirlimbs and strong claws are admirably adapted for crawling overthe rugged and fissured masses of lava, which everywhere formthe coast. In such situations, a group of six or seven ofthese hideous reptiles may oftentimes be seen on the blackrocks, a few feet above the surf, basking in the sun withoutstretched legs.
I opened the stomachs of several, and found them largelydistended with minced sea-weed (Ulvae), which grows inthin foliaceous expansions of a bright green or a dull redcolour. I do not recollect having observed this sea-weed inany quantity on the tidal rocks; and I have reason to believeit grows at the bottom of the sea, at some little distance fromthe coast. If such be the case, the object of these animalsoccasionally going out to sea is explained. The stomachcontained nothing but the sea-weed. Mr. Baynoe, however, founda piece of crab in one; but this might have got in accidentally,in the same manner as I have seen a caterpillar, inthe midst of some lichen, in the paunch of a tortoise. Theintestines were large, as in other herbivorous animals. Thenature of this lizard's food, as well as the structure of itstail and feet, and the fact of its having been seen voluntarilyswimming out at sea, absolutely prove its aquatic habits;yet there is in this respect one strange anomaly, namely, thatwhen frightened it will not enter the water. Hence it iseasy to drive these lizards down to any little point overhangingthe sea, where they will sooner allow a person to catchhold of their tails than jump into the water. They do notseem to have any notion of biting; but when much frightenedthey squirt a drop of fluid from each nostril. I threw oneseveral times as far as I could, into a deep pool left by theretiring tide; but it invariably returned in a direct line tothe spot where I stood. It swam near the bottom, with avery graceful and rapid movement, and occasionally aideditself over the uneven ground with its feet. As soon as itarrived near the edge, but still being under water, it tried toconceal itself in the tufts of sea-weed, or it entered somecrevice. As soon as it thought the danger was past, itcrawled out on the dry rocks, and shuffled away as quicklyas it could. I several times caught this same lizard, by drivingit down to a point, and though possessed of such perfectpowers of diving and swimming, nothing would induce it toenter the water; and as often as I threw it in, it returned inthe manner above described. Perhaps this singular piece ofapparent stupidity may be accounted for by the circumstance,that this reptile has no enemy whatever on shore,whereas at sea it must often fall a prey to the numeroussharks. Hence, probably, urged by a fixed and hereditaryinstinct that the shore is its place of safety, whatever theemergency may be, it there takes refuge.
During our visit (in October), I saw extremely few smallindividuals of this species, and none I should think undera year old. From this circumstance it seems probable thatthe breeding season had not then commenced. I asked severalof the inhabitants if they knew where it laid its eggs:they said that they knew nothing of its propagation, althoughwell acquainted with the eggs of the land kind -- a fact,considering how very common this lizard is, not a littleextraordinary.
We will now turn to the terrestrial species (A. Demarlii),with a round tail, and toes without webs. This lizard,instead of being found like the other on all the islands, isconfined to the central part of the archipelago, namely toAlbemarle, James, Barrington, and Indefatigable islands. Tothe southward, in Charles, Hood, and Chatham islands, andto the northward, in Towers, Bindloes, and Abingdon, Ineither saw nor heard of any. It would appear as if it hadbeen created in the centre of the archipelago, and thence hadbeen dispersed only to a certain distance. Some of theselizards inhabit the high and damp parts of the islands, butthey are much more numerous in the lower and steriledistricts near the coast. I cannot give a more forcible proofof their numbers, than by stating that when we were left atJames Island, we could not for some time find a spot freefrom their burrows on which to pitch our single tent. Liketheir brothers the sea-kind, they are ugly animals, of ayellowish orange beneath, and of a brownish red colour above:from their low facial angle they have a singularly stupidappearance. They are, perhaps, of a rather less size than themarine species; but several of them weighed between ten andfifteen pounds. In their movements they are lazy and halftorpid. When not frightened, they slowly crawl along withtheir tails and bellies dragging on the ground. They oftenstop, and doze for a minute or two, with closed eyes and hindlegs spread out on the parched soil.
They inhabit burrows, which they sometimes make betweenfragments of lava, but more generally on level patches of thesoft sandstone-like tuff. The holes do not appear to be verydeep, and they enter the ground at a small angle; so thatwhen walking over these lizard-warrens, the soil is constantlygiving way, much to the annoyance of the tired walker. Thisanimal, when making its burrow, works alternately the oppositesides of its body. One front leg for a short timescratches up the soil, and throws it towards the hind foot,which is well placed so as to heave it beyond the mouth ofthe hole. That side of the body being tired, the other takesup the task, and so on alternately. I watched one for a longtime, till half its body was buried; I then walked up and pulledit by the tail, at this it was greatly astonished, and soonshuffled up to see what was the matter; and then stared mein the face, as much as to say, "What made you pull mytail?"
They feed by day, and do not wander far from their burrows;if frightened, they rush to them with a most awkwardgait. Except when running down hill, they cannot movevery fast, apparently from the lateral position of their legs.They are not at all timorous: when attentively watching anyone, they curl their tails, and, raising themselves on theirfront legs, nod their heads vertically, with a quick movement,and try to look very fierce; but in reality they are not at allso: if one just stamps on the ground, down go their tails,and off they shuffle as quickly as they can. I have frequentlyobserved small fly-eating lizards, when watching anything,nod their heads in precisely the same manner; but I do notat all know for what purpose. If this Amblyrhynchus is heldand plagued with a stick, it will bite it very severely; butI caught many by the tail, and they never tried to bite me.If two are placed on the ground and held together, they willfight, and bite each other till blood is drawn.
The individuals, and they are the greater number, whichinhabit the lower country, can scarcely taste a drop of waterthroughout the year; but they consume much of the succulentcactus, the branches of which are occasionally broken offby the wind. I several times threw a piece to two or threeof them when together; and it was amusing enough to seethem trying to seize and carry it away in their mouths, likeso many hungry dogs with a bone. They eat very deliberately,but do not chew their food. The little birds are awarehow harmless these creatures are: I have seen one of thethick-billed finches picking at one end of a piece of cactus(which is much relished by all the animals of the lowerregion), whilst a lizard was eating at the other end; andafterwards the little bird with the utmost indifference hoppedon the back of the reptile.
I opened the stomachs of several, and found them full ofvegetable fibres and leaves of different trees, especially ofan acacia. In the upper region they live chiefly on the acidand astringent berries of the guayavita, under which treesI have seen these lizards and the huge tortoises feedingtogether. To obtain the acacia-leaves they crawl up the lowstunted trees; and it is not uncommon to see a pair quietlybrowsing, whilst seated on a branch several feet above theground. These lizards, when cooked, yield a white meat,which is liked by those whose stomachs soar above allprejudices.
Humboldt has remarked that in intertropical SouthAmerica, all lizards which inhabit dry regions are esteemeddelicacies for the table. The inhabitants state that thosewhich inhabit the upper damp parts drink water, but thatthe others do not, like the tortoises, travel up for it fromthe lower sterile country. At the time of our visit, thefemales had within their bodies numerous, large, elongatedeggs, which they lay in their burrows: the inhabitants seekthem for food.
These two species of Amblyrhynchus agree, as I havealready stated, in their general structure, and in many oftheir habits. Neither have that rapid movement, socharacteristic of the genera Lacerta and Iguana. They are bothherbivorous, although the kind of vegetation on which theyfeed is so very different. Mr. Bell has given the name to thegenus from the shortness of the snout: indeed, the form ofthe mouth may almost be compared to that of the tortoise:one is led to suppose that this is an adaptation to theirherbivorous appetites. It is very interesting thus to find awell-characterized genus, having its marine and terrestrialspecies, belonging to so confined a portion of the world. Theaquatic species is by far the most remarkable, because it isthe only existing lizard which lives on marine vegetableproductions. As I at first observed, these islands are not soremarkable for the number of the species of reptiles, as forthat of the individuals, when we remember the well-beatenpaths made by the thousands of huge tortoises -- the manyturtles -- the great warrens of the terrestrial Amblyrhynchus-- and the groups of the marine species basking on the coast-rocks of every island -- we must admit that there is no otherquarter of the world where this Order replaces the herbivorousmammalia in so extraordinary a manner. The geologiston hearing this will probably refer back in his mind to theSecondary epochs, when lizards, some herbivorous, somecarnivorous, and of dimensions comparable only with ourexisting whales, swarmed on the land and in the sea. It is,therefore, worthy of his observation, that this archipelago,instead of possessing a humid climate and rank vegetation,cannot be considered otherwise than extremely arid, and, foran equatorial region, remarkably temperate.
To finish with the zoology: the fifteen kinds of sea-fishwhich I procured here are all new species; they belong totwelve genera, all widely distributed, with the exception ofPrionotus, of which the four previously known species liveon the eastern side of America. Of land-shells I collectedsixteen kinds (and two marked varieties, of which, with theexception of one Helix found at Tahiti, all are peculiar tothis archipelago: a single fresh-water shell (Paludina) iscommon to Tahiti and Van Diemen's Land. Mr. Cuming,before our voyage procured here ninety species of sea-shells,and this does not include several species not yet specificallyexamined, of Trochus, Turbo, Monodonta, and Nassa. Hehas been kind enough to give me the following interestingresults: Of the ninety shells, no less than forty-seven areunknown elsewhere -- a wonderful fact, considering howwidely distributed sea-shells generally are. Of the forty-three shells found in other parts of the world, twenty-fiveinhabit the western coast of America, and of these eight aredistinguishable as varieties; the remaining eighteen (includingone variety) were found by Mr. Cuming in the LowArchipelago, and some of them also at the Philippines. Thisfact of shells from islands in the central parts of the Pacificoccurring here, deserves notice, for not one single sea-shell isknown to be common to the islands of that ocean and to thewest coast of America. The space of open sea running northand south off the west coast, separates two quite distinctconchological provinces; but at the Galapagos Archipelagowe have a halting-place, where many new forms have beencreated, and whither these two great conchological provinceshave each sent up several colonists. The American provincehas also sent here representative species; for there is aGalapageian species of Monoceros, a genus only found on thewest coast of America; and there are Galapageian speciesof Fissurella and Cancellaria, genera common on the westcoast, but not found (as I am informed by Mr. Cuming) inthe central islands of the Pacific. On the other hand, thereare Galapageian species of Oniscia and Stylifer, genera commonto the West Indies and to the Chinese and Indian seas,but not found either on the west coast of America or in thecentral Pacific. I may here add, that after the comparisonby Messrs. Cuming and Hinds of about 2000 shells fromthe eastern and western coasts of America, only one singleshell was found in common, namely, the Purpura patula,which inhabits the West Indies, the coast of Panama,and the Galapagos. We have, therefore, in this quarterof the world, three great conchological sea-provinces, quitedistinct, though surprisingly near each other, being separatedby long north and south spaces either of land or ofopen sea.
I took great pains in collecting the insects, but exceptingTierra del Fuego, I never saw in this respect so poor a country.Even in the upper and damp region I procured very few,excepting some minute Diptera and Hymenoptera, mostly ofcommon mundane forms. As before remarked, the insects,for a tropical region, are of very small size and dull colours.Of beetles I collected twenty-five species (excluding aDermestes and Corynetes imported, wherever a ship touches);of these, two belong to the Harpalidae, two to theHydrophilidae, nine to three families of the Heteromera, and theremaining twelve to as many different families. Thiscircumstance of insects (and I may add plants), where few innumber, belonging to many different families, is, I believe,very general. Mr. Waterhouse, who has published
The botany of this group is fully as interesting as thezoology. Dr. J. Hooker will soon publish in the "LinneanTransactions" a full account of the Flora, and I am muchindebted to him for the following details. Of floweringplants there are, as far as at present is known, 185 species,and 40 cryptogamic species, making altogether 225; of thisnumber I was fortunate enough to bring home 193. Of theflowering plants, 100 are new species, and are probably confinedto this archipelago. Dr. Hooker conceives that, of theplants not so confined, at least 10 species found near thecultivated ground at Charles Island, have been imported.It is, I think, surprising that more American species havenot been introduced naturally, considering that the distanceis only between 500 and 600 miles from the continent, andthat (according to Collnet, p. 58) drift-wood, bamboos, canes,and the nuts of a palm, are often washed on the south-easternshores. The proportion of 100 flowering plants out of 183(or 175 excluding the imported weeds) being new, is sufficient,I conceive, to make the Galapagos Archipelago a distinctbotanical province; but this Flora is not nearly sopeculiar as that of St. Helena, nor, as I am informed byDr. Hooker, of Juan Fernandez. The peculiarity of theGalapageian Flora is best shown in certain families; -- thusthere are 21 species of Compositae, of which 20 are peculiarto this archipelago; these belong to twelve genera, and ofthese genera no less than ten are confined to the archipelago!Dr. Hooker informs me that the Flora has an undoubtedlyWestern American character; nor can he detect in it anyaffinity with that of the Pacific. If, therefore, we except theeighteen marine, the one fresh-water, and one land-shell,which have apparently come here as colonists from thecentral islands of the Pacific, and likewise the one distinctPacific species of the Galapageian group of finches, we seethat this archipelago, though standing in the Pacific Ocean,is zoologically part of America.
If this character were owing merely to immigrants fromAmerica, there would be little remarkable in it; but we seethat a vast majority of all the land animals, and that morethan half of the flowering plants, are aboriginal productionsIt was most striking to be surrounded by new birds, newreptiles, new shells, new insects, new plants, and yet byinnumerable trifling details of structure, and even by the tonesof voice and plumage of the birds, to have the temperate plainsof Patagonia, or rather the hot dry deserts of Northern Chile,vividly brought before my eyes. Why, on these small pointsof land, which within a late geological period must havebeen covered by the ocean, which are formed by basaltic lava,and therefore differ in geological character from the Americancontinent, and which are placed under a peculiar climate,-- why were their aboriginal inhabitants, associated, I mayadd, in different proportions both in kind and number fromthose on the continent, and therefore acting on each otherin a different manner -- why were they created on Americantypes of organization? It is probable that the islands of theCape de Verd group resemble, in all their physical conditions,far more closely the Galapagos Islands, than these latterphysically resemble the coast of America, yet the aboriginalinhabitants of the two groups are totally unlike; those of theCape de Verd Islands bearing the impress of Africa, asthe inhabitants of the Galapagos Archipelago are stampedwith that of America
I have not as yet noticed by far the most remarkable featurein the natural history of this archipelago; it is, thatthe different islands to a considerable extent are inhabited bya different set of beings. My attention was first called tothis fact by the Vice-Governor, Mr. Lawson, declaring thatthe tortoises differed from the different islands, and that hecould with certainty tell from which island any one wasbrought. I did not for some time pay sufficient attentionto this statement, and I had already partially mingled togetherthe collections from two of the islands. I neverdreamed that islands, about 50 or 60 miles apart, and most ofthem in sight of each other, formed of precisely the samerocks, placed under a quite similar climate, rising to a nearlyequal height, would have been differently tenanted; but weshall soon see that this is the case. It is the fate of mostvoyagers, no sooner to discover what is most interesting inany locality, than they are hurried from it; but I ought,perhaps, to be thankful that I obtained sufficient materials toestablish this most remarkable fact in the distribution oforganic beings.
The inhabitants, as I have said, state that they can distinguishthe tortoises from the different islands; and thatthey differ not only in size, but in other characters. CaptainPorter has described
If we now turn to the Flora, we shall find the aboriginalplants of the different islands wonderfully different. I giveall the following results on the high authority of my friendDr. J. Hooker. I may premise that I indiscriminately collectedeverything in flower on the different islands, and fortunatelykept my collections separate. Too much confidence,however, must not be placed in the proportional results, asthe small collections brought home by some other naturaliststhough in some respects confirming the results, plainly showthat much remains to be done in the botany of this group:the Leguminosae, moreover, has as yet been only approximatelyworked out: --
The distribution of the tenants of this archipelago wouldnot be nearly so wonderful, if, for instance, one island hada mocking-thrush, and a second island some other quite distinctgenus, -- if one island had its genus of lizard, and asecond island another distinct genus, or none whatever; -- orif the different islands were inhabited, not by representativespecies of the same genera of plants, but by totally differentgenera, as does to a certain extent hold good: for, to giveone instance, a large berry-bearing tree at James Island hasno representative species in Charles Island. But it is thecircumstance, that several of the islands possess their ownspecies of the tortoise, mocking-thrush, finches, and numerousplants, these species having the same general habits,occupying analogous situations, and obviously filling thesame place in the natural economy of this archipelago, thatstrikes me with wonder. It may be suspected that some ofthese representative species, at least in the case of thetortoise and of some of the birds, may hereafter prove to beonly well-marked races; but this would be of equally greatinterest to the philosophical naturalist. I have said that mostof the islands are in sight of each other: I may specify thatCharles Island is fifty miles from the nearest part of ChathamIsland, and thirty-three miles from the nearest part ofAlbemarle Island. Chatham Island is sixty miles from thenearest part of James Island, but there are two intermediateislands between them which were not visited by me. JamesIsland is only ten miles from the nearest part of AlbemarleIsland, but the two points where the collections were madeare thirty-two miles apart. I must repeat, that neither thenature of the soil, nor height of the land, nor the climate,nor the general character of the associated beings, andtherefore their action one on another, can differ much in thedifferent islands. If there be any sensible difference in theirclimates, it must be between the Windward group (namely,Charles and Chatham Islands), and that to leeward; butthere seems to be no corresponding difference in the productionsof these two halves of the archipelago.
The only light which I can throw on this remarkable differencein the inhabitants of the different islands, is, thatvery strong currents of the sea running in a westerly andW.N.W. direction must separate, as far as transportal by thesea is concerned, the southern islands from the northernones; and between these northern islands a strong N.W. currentwas observed, which must effectually separate Jamesand Albemarle Islands. As the archipelago is free to amost remarkable degree from gales of wind, neither thebirds, insects, nor lighter seeds, would be blown from islandto island. And lastly, the profound depth of the ocean betweenthe islands, and their apparently recent (in a geologicalsense) volcanic origin, render it highly unlikely that theywere ever united; and this, probably, is a far more importantconsideration than any other, with respect to the geographicaldistribution of their inhabitants. Reviewing the factshere given, one is astonished at the amount of creative force,if such an expression may be used, displayed on these small,barren, and rocky islands; and still more so, at its diverseyet analogous action on points so near each other. I havesaid that the Galapagos Archipelago might be called a satelliteattached to America, but it should rather be called agroup of satellites, physically similar, organically distinct,yet intimately related to each other, and all related in amarked, though much lesser degree, to the great Americancontinent.
I will conclude my description of the natural history ofthese islands, by giving an account of the extreme tamenessof the birds.
This disposition is common to all the terrestrial species;namely, to the mocking-thrushes, the finches, wrens, tyrant-flycatchers, the dove, and carrion-buzzard. All of them areoften approached sufficiently near to be killed with a switch,and sometimes, as I myself tried, with a cap or hat. A gunis here almost superfluous; for with the muzzle I pushed ahawk off the branch of a tree. One day, whilst lying down,a mocking-thrush alighted on the edge of a pitcher, made ofthe shell of a tortoise, which I held in my hand, and beganvery quietly to sip the water; it allowed me to lift it fromthe ground whilst seated on the vessel: I often tried, andvery nearly succeeded, in catching these birds by their legs.Formerly the birds appear to have been even tamer than atpresent. Cowley (in the year 1684) says that the "Turtledoveswere so tame, that they would often alight on our hatsand arms, so as that we could take them alive, they not fearingman, until such time as some of our company did fire atthem, whereby they were rendered more shy." Dampieralso, in the same year, says that a man in a morning's walkmight kill six or seven dozen of these doves. At present,although certainly very tame, they do not alight on people'sarms, nor do they suffer themselves to be killed in such largenumbers. It is surprising that they have not become wilder;for these islands during the last hundred and fifty years havebeen frequently visited by bucaniers and whalers; and thesailors, wandering through the wood in search of tortoises,always take cruel delight in knocking down the little birds.These birds, although now still more persecuted, do notreadily become wild. In Charles Island, which had thenbeen colonized about six years, I saw a boy sitting by a wellwith a switch in his hand, with which he killed the dovesand finches as they came to drink. He had already procureda little heap of them for his dinner, and he said that he hadconstantly been in the habit of waiting by this well for thesame purpose. It would appear that the birds of thisarchipelago, not having as yet learnt that man is a moredangerous animal than the tortoise or the Amblyrhynchus,disregard him, in the same manner as in England shy birds, suchas magpies, disregard the cows and horses grazing in our fields.
The Falkland Islands offer a second instance of birdswith a similar disposition. The extraordinary tameness ofthe little Opetiorhynchus has been remarked by Pernety,Lesson, and other voyagers. It is not, however, peculiar tothat bird: the Polyborus, snipe, upland and lowland goose,thrush, bunting, and even some true hawks, are all more orless tame. As the birds are so tame there, where foxes,hawks, and owls occur, we may infer that the absence of allrapacious animals at the Galapagos, is not the cause of theirtameness here. The upland geese at the Falklands show, bythe precaution they take in building on the islets, that theyare aware of their danger from the foxes; but they are notby this rendered wild towards man. This tameness of thebirds, especially of the waterfowl, is strongly contrasted withthe habits of the same species in Tierra del Fuego, where forages past they have been persecuted by the wild inhabitants.In the Falklands, the sportsman may sometimes kill moreof the upland geese in one day than he can carry home;whereas in Tierra del Fuego it is nearly as difficult to killone, as it is in England to shoot the common wild goose.
In the time of Pernety (1763), all the birds there appearto have been much tamer than at present; he states that theOpetiorhynchus would almost perch on his finger; and thatwith a wand he killed ten in half an hour. At that periodthe birds must have been about as tame as they now are atthe Galapagos. They appear to have learnt caution moreslowly at these latter islands than at the Falklands, wherethey have had proportionate means of experience; for besidesfrequent visits from vessels, those islands have been atintervals colonized during the entire period. Even formerly,when all the birds were so tame, it was impossible by Pernety'saccount to kill the black-necked swan -- a bird ofpassage, which probably brought with it the wisdom learntin foreign countries.
I may add that, according to Du Bois, all the birds atBourbon in 1571-72, with the exception of the flamingoesand geese, were so extremely tame, that they could be caughtby the hand, or killed in any number with a stick. Again,at Tristan d'Acunha in the Atlantic, Carmichael