Fossils, Finches and Fuegians: Charles Darwin’s Adventures and Discoveries on the Beagle

On 25 April Charles suffered on a small scale what he described as some of the horrors of a shipwreck, when two or three large waves swamped the boat from which he was landing his possessions to transfer them to Botafogo, though nothing was completely spoiled. The following day he wrote an account of the disaster to his sister Caroline, also reporting to her:

I send in a packet, my commonplace Journal. I have taken a fit of disgust with it & want to get it out of my sight. Any of you that like may read it, a great deal is absolutely childish. Remember however this, that it is written solely to make me remember this voyage, & that it is not a record of facts but of my thoughts, & in excuse recollect how tired I generally am when writing it … Be sure you mention the receiving of my journal, as anyhow to me it will be of considerable future interest as an exact record of all my first impressions, & such a set of vivid ones they have been must make this period of my life always one of interest to myself. If you will speak quite sincerely, I should be glad to have your criticisms. Only recollect the above mentioned apologies.60

During the next few days Charles was taken by FitzRoy to dine more than once with Mr Aston, representative of the English government, at meals which to his surprise ‘from the absence of all form almost resembled a Cambridge party’. He also dined with the Admiral, Sir Thomas Baker, no doubt with the greater formality of the Navy, and was taken to watch the impressive spectacle of an official inspection of the seventy-four-gun battleship Warspite.

A week later the Beagle sailed back to Bahia to find an explanation for the discrepancy of four miles in the meridian distance between the Abrolhos Islands and Rio de Janeiro shown in Baron Roussin’s chart as compared with the Beagle’s measurements. In a private letter to FitzRoy, Beaufort later commended his ‘daring’ for thus having turned back without prior instruction from the Admiralty.61 It turned out that Baron Roussin’s placing of the Abrolhos was correct, but not that of Rio, confirming that FitzRoy’s twenty-two chronometers and his dependence on a connected chain of meridian distances was the most reliable method of finding the precise longitude. This information was duly conveyed to the French commander-in-chief at Rio.

A less happy piece of news was that three members of a party who had sailed in the ship’s cutter to the river Macacu shortly before the Beagle’s departure – an extraordinarily powerful seaman called Morgan, Boy Jones who had just been promised promotion, and Charles’s young friend Midshipman Musters – had been stricken with fatal attacks of malaria a few days later, and were buried at Bahia. FitzRoy considered that the danger of contracting the disease appeared to be greatest while sleeping, while Charles found it puzzling that the fever so often came on several days after the victim had returned to a seemingly pure atmosphere. The full details of the role of mosquitoes as the vector in the transmission of malaria were made clear by Sir Ronald Ross only in 1897.

For the next two months Charles assiduously explored Rio and the surrounding country, and on alternate days wrote up his notes and sorted out the specimens that he had collected, for he found that one hour’s collecting often kept him busy for the rest of the day. He noted that whereas ‘The naturalist in England enjoys in his walks a great advantage over others in frequently meeting something worthy of attention; here he suffers a pleasant nuisance in not being able to walk a hundred yards without being fairly tied to the spot by some new & wondrous creature.’ A discovery that particularly thrilled him was to find in the forest what was evidently a species of flatworm related to Cuvier’s Planaria, but which he thought was generally regarded as a strictly marine animal. He wrote:

June 17th. This very extraordinary animal was found, under the bark of a decaying tree, in the forest at a considerable elevation. The place was quite dry & no water at all near. Body soft, parenchymatous,* covered with slime (like snails & leaving a track), not much flattened. When fully extended, 2 & ¼ inches long: in broardest parts only .13 wide. Back arched, top rather flat; beneath, a level crawling surface (precisely resembles a gasteropode [snail], only not separated from the body), with a slightly projecting membranous edge. Anterior end extremely extensible, pointed lengthened; posterior half of body broardest, tail bluntly pointed.

Colours: back with glossy black stripe; on each side of this a primrose white one edged externally with black; these stripes reach to extremities, & become uniformly narrower. sides & foot dirty “orpiment orange”. From the elegance of shape & great beauty of colours, the animal had a very striking appearance.

The anterior extremity of foot rather grooved or arched. On its edge is a regular row of round black dots (as in marine Planariæ) which are continued round the foot, but not regularly; foot thickly covered with very minute angular white marks or specks. On the foot in centre, about 1/3 of length from the tail, is an irregular circular white space, free from the specks. Extending through the whole width of this, is a transverse slit, sides straight parallel, extremities rounded, 1/60th of inch long, tolerably apparent (i.e. with my very weak lens).62

The colours in inverted commas quoted by Charles in this and other descriptions of his specimens were taken from a neat little colour atlas by Patrick Syme in the Beagle’s library, of which Charles made frequent use. The copy of this atlas that survived among his books at Down House in Kent is, however, spotless, so that the Beagle’s hard-worked copy evidently had to be replaced after his return to England. In a letter to Henslow begun on 23 July 1832, Charles said: ‘Amongst the lower animals, nothing has so much interested me as finding 2 species of elegantly coloured true Planariæ, inhabiting the dry forest! The false relation they bear to snails is the most extraordinary thing of the kind I have ever seen. In the same genus (or more truly family) some of the marine species possess an organization so marvellous that I can scarcely credit my eyesight.’63 Henslow was unconvinced, and on page 5 of the edition of Charles’s letters to him printed for private distribution by the Cambridge Philosophical Society in 1835, the word ‘true’ was omitted, and ‘(?)’ was added after ‘Planariæ’. Charles’s observations on the anatomy and behaviour of these flatworms were nevertheless mainly correct, except that he thought they fed on decayed wood, whereas in fact they are carnivorous.

Charles was taken hunting one day by a wealthy priest who had a pack of five exotically-named dogs that were released into a forest of huge trees and left to pursue their own small deer and other game. In the intervals, the hunters with guns shot toucans and beautiful little green parrots in a rather aimless fashion. Charles was taken to see a bearded monkey shot the previous day, but did not record having seen a live one.

Once again he was disappointed in the Brazilian birds, which made surprisingly little show in their native country. One of the most characteristic sounds in Rio today is the repeated call of the tyrantflycatchers, but they do not possess the harmonious voice of the crotophaga, related to the parrots, of which Charles brought back a specimen with a stomachful of insects.

Better vocalists were found elsewhere, for in torrents of rain that soaked the fields he found a toad that sang through its nose at a high pitch, and then an equally musical frog:

On the back, a band of “yellowish brown” width of head, sides copper yellow; abdomen silvery yellowish white slightly tuberculated: beneath the mouth, smooth dark yellow; under sides of legs leaden flesh colour. Can adhere to perpendicular surface of glass. The fields resound with the noise which this little animal, as it sits on a blade of grass about an inch from the water, emits. The note is very musical. I at first thought it must be a bird. When several are together they chirp in harmony; each beginning a lower note than the other, & then continuing upon two (I think these notes are thirds to each other).

In addition to its ability to climb up a sheet of glass, the musician had some interesting parasites on its skin, and these too were preserved for identification.

A favourite excursion made by Charles several times with friends from the Beagle was to climb to the summit of the Corcovado mountain, a huge mass of naked granite looking down on Rio, where a century later the huge statue of Christ would be erected. On 30 May, Charles took his mountain barometer with him, and determined the height of the mountain to be 2225 feet above sea level, though possibly the figure of 2330 feet obtained on another occasion by Captain P.P. King was more reliable.

It was while he was in Rio that Charles wrote to Henslow: ‘I am at present red-hot with spiders, they are very interesting, & if I am not mistaken, I have already taken some new genera.’ He had indeed, and one of his captures was a crab spider of the family Thomisidae:

Evidently by its four front strong equal legs being much longer than posterior; by its habits on a leaf of a tree, is a Laterigrade: It differs however most singularly from that tribe & is I think a new genus. Eyes 10 in number, (!?) anterior ones red, situated on two curved longitudinal lines, thus the central triangular ones on an eminence: Machoires rounded inclined: languettes bluntly arrow shaped: Cheliceres powerful with large aperture for poison. Abdomen encrusted & with 5 conical peaks: Thorax with one small one: Crotchets to Tarsi, very strong (& with 2 small corresponding ones beneath?) Colour snow white, except tarsi & half of leg bright yellow. also tops of abdominal points & line of eyes black. It must I think be new. Lithetron paradoxicus Darwin!!! Taken in the forest.65

Charles’s occasional lapses into French in his notes were the consequence of his dependence on books by the encyclopédistes Cuvier, Lamarck, Lamouroux and others in the Beagle’s library, his favourite being the seventeen volumes of the Dictionnaire classique d’histoire naturelle, edited by Jean Baptiste Genevieve Marcellin Bory de Saint-Vincent.

Although spiders are important insect predators, Charles found that sometimes the tables were turned, for he came upon wasps known as mud daubers of the family Sphecidae that hunt spiders as food for their larvae. He wrote:

I have frequently observed these insects carrying dead spiders, even the powerful genus Mygalus, & have found the clay cells made for their larvæ, filled with dying & dead small spiders: to day (June 2d) I watched a contest between one of them & a large Lycosa. The insect dashed against the spider & then flew away; it had evidently mortially [sic] wounded its enemy with its sting; for the spider crawled a little way & then rolled down the hill & scrambled into a tuft of grass. The Hymenoptera [wasp] most assuredly again found out the spider by the power of smell; regularly making small circuits (like a dog) & rapidly vibrating its wings & antennæ: It was a most curious spectacle: the Spider had yet some life, & the Hymenop was most cautious to keep clear of the jaws; at last being stung twice more on under side of the thorax it became motionless. The hymenop. apparently ascertained this by repeatedly putting its head close to the spider, & then dragged away the heavy Lycosa with its mandibles. I then took them both.65

‘Whilst on board the Beagle,’ wrote Charles in his Autobiography, ‘I was quite orthodox, and I remember being heartily laughed at by several of the officers (though themselves orthodox) for quoting the Bible as an unanswerable authority on some point of morality.’ So at this time he had not yet begun to think seriously about the manner in which new species of animals might come into being, and his orthodoxy included a belief in a world tenanted by constant species that had originated at specific centres of creation. Since he was well-versed by now in the first two volumes of Charles Lyell’s Principles of Geology, this does not of course mean that he subscribed to the absolute truth of the first book of Genesis, nor to the accuracy of Bishop Usher’s calculations of the age of the earth. But he had been impressed at Cambridge by William Paley’s argument in his Natural Theology that in looking at the living world ‘The marks of design are too strong to be gotten over. Design must have had a designer. That designer must have been a person. That person is God.’ In due course his faith in Paley waned, but as will be seen he continued to speak of a Creator in his notes until 1836, so that specifically on the evolutionary front his thoughts had not yet moved far when he was in Brazil.

All the same, he had already made significant advances in two important biological fields of which he was one of the founding fathers. Thus from the very beginning of the voyage he regarded the behaviour of the animals he observed as equal in importance to the anatomical differences between them in distinguishing between species. A good example was provided by his comments on the butterfly Papilio feronia:

This insect is not uncommon & generally frequents the Orange groves; it is remarkable in several respects. It flies high & continually settles on the trunks of trees; invariably with its head downwards & with its wings expanded or opened to beyond the horizontal plane. It is the only butterfly I ever saw make use of its legs in running, this one will avoid being caught by shuffling to one side. Some time ago I saw several pairs, I presume males & females, of butterflies chasing each other, & which from appearance & habits were I am sure the same species as this. Strange as it may sound, they when fluttering about emitted a noise somewhat similar to cocking a small pistol; a sort of a click. I observed it repeatedly. June 28th. In same place I observed one of these butterflies resting as described on a trunk of tree; another happening to fly past, immediately they chased each other, emitting (& there could be no mistake the space being open) the peculiar noise: this is continued for some time & is more like a small toothed wheel passing under a spring pawl. – The noise would be heard about 20 yards distant. This fact would appear to be new.66

A preliminary examination of a specimen of the butterfly in 1837 by G.R. Waterhouse at the London Zoological Society provided no explanation for the source of the peculiar noise, but a few years later it was found by another entomologist that it was produced by a sort of drum at the base of the fore wings, together with a screw-like diaphragm in the interior.

Another important branch of biology in which Charles was a leading pioneer, along with Linnaeus, Buffon and Humboldt, is the study of mutual relations between animals and their environment, for which the term ‘ecology’ was introduced in 1873. Here too, Charles’s basically new way of thinking was apparent from the first in his notes. Summarising his general observations on what he had seen in Rio, he wrote:

I could not help noticing how exactly the animals & plants in each region are adapted to each other. Every one must have noticed how Lettuces & Cabbages suffer from the attacks of Caterpillars & Snails. But when transplanted here in a foreign clime, the leaves remain as entire as if they contained poison. Nature, when she formed these animals & these plants, knew they must reside together.

Referring to collections of insects he had made on the shore behind the Sugar Loaf in Rio, he said that since the situation was much the same as that of Barmouth when he was collecting there in August 1828, many of the species would be closely allied. On another occasion he wrote:

In my geological notes I have mentioned the lagoons on the coast which contain either salt or fresh water. The Lagoa near the Botanic Garden is one of this class. The water is not so salt as the sea, for only once in the year a passage is cut for sake of the fishes. The beach is composed of large grains of quartz & very clean. If cemented into a breccia or sandstone it would precisely resemble a rock at Bahia containing marine shells. A small Turbo [a turban snail] appeared the only proper inhabitant, & thus differed from the lagoons on the Northern coast in the absence of those large bodies of Bivalves. I was surprised on the borders to see a few Hydrophili [water beetles] inhabiting this salt water, & some Dolimedes [a nursery web spider] running on the surface.

CHAPTER 7

An Unquiet Trip from Monte Video to Buenos Aires

At nine o’clock in the morning on 5 July the Beagle sailed out of the harbour at Rio on a gentle breeze, hailed by a salute of hearty cheers from the crews of HMS Warspite and HMS Samarang. FitzRoy noted with some satisfaction that ‘Strict etiquette might have been offended at such a compliment to a little ten-gun brig, or indeed to any vessel unless she were going out to meet an enemy, or were returning into port victorious: but although not about to encounter a foe, our lonely vessel was going to undertake a task laborious, and often dangerous, to the zealous execution of which the encouragement of our brother-seamen was no trifling enducement.’

For the next three weeks the Beagle sailed on to the south, sometimes in light winds when progress was disappointingly slow, sometimes in gales when even the sight of a whale possessed little interest to Charles’s jaundiced eyes, but best when the studding sails were ‘alow & aloft – that is wind abaft the beam & favourable’. On the morning of 14 July Charles noted:

I was much interested by watching a large herd of Grampuses, which followed the ship for some time. They were about 15 feet in length, & generally rose together, cutting & splashing the water with great violence. In the distance some whales were seen blowing. All these have been the black whale. The Spermaceti is the sort which the Southern Whalers pursue.

The grampuses, which on this occasion were genuine ones, were probably a group of juvenile pilot whales, totally black in colour, with bulging foreheads full of sperm oil.

Four days later, Charles wrote:

A wonderful shoal of Porpoises, at least many hundreds in number, crossed the bows of our vessel. The whole sea in places was furrowed by them. They proceeded by jumps in which the whole body was exposed, & as hundreds thus cut the water it presented a most extraordinary spectacle. When the ship was running 9 knots these animals could with the greatest ease cross & recross our bows & then dash away right ahead, thus showing off to us their great strength & activity.

The Beagle sailed on in the variable weather characteristic of the entrance to the Rio Plata. Close to the mouth of the river on a particularly dirty night, the ship was surrounded by penguins and seals which made such curious noises that the Master reported to the First Lieutenant that he had heard cattle lowing on the shore. On the morning of 26 July, the Beagle’s anchoring at Monte Video was, according to Charles, quickly followed by the arrival alongside of six heavily-armed boats from the frigate HMS Druid, containing forty marines and a hundred sailors. The frigate’s Captain Hamilton explained that the current military government had just seized four hundred horses belonging to a British subject, and that he aimed to provide sufficient visible support for the opposition party to bring about a restitution of the horses.* It seemed that such disputes were usually won without bloodshed by the side that succeeded in looking the stronger. This episode was an eye-opener for Charles on the vagaries of South American politics, but FitzRoy did not regard the incident as worthy of mention in his account of the day, merely recording that he was occupied with observations for his chronometers, and preparing for surveying the coasts south of the Rio Plata.

On the following morning, FitzRoy and Charles landed on Rat Island, where one of them took sights, while the other found, but did not preserve, a species of legless lizard known as a skink. On 28 July Charles visited the Mount, the little hill 450 feet high that dominated the district and gave Monte Video its name. He decided that the view from the summit was the most uninteresting that he had ever seen – like Cambridgeshire but without even any trees.

Two days later, FitzRoy got wind of the remains of some hydrographical information collected by Spain that was preserved in the archives of Buenos Aires, and on 2 August the Beagle sailed to the south bank of the Rio Plata in search of it. As explained by Charles, they had a disconcerting reception:

We certainly are a most unquiet ship; peace flies before our steps. On entering the outer roadstead, we passed a Buenos Ayres guard-ship. When abreast of her she fired an empty gun, we not understanding this sailed on, & in a few minutes another discharge was accompanied by the whistling of a shot over our rigging. Before she could get another gun ready we had passed her range. When we arrived at our anchorage, which is more than three miles distant from the landing place, two boats were lowered, & a large party started in order to stay some days in the city. Wickham went with us, & intended immediately going to Mr Fox, the English minister, to inform him of the insult offered to the British flag. When close to the shore, we were met by a Quarantine boat which said we must all return on board, to have our bill of health inspected, from fears of the Cholera. Nothing which we could say about being a man of war, having left England 7 months & lying in an open roadstead, had any effect. They said we ought to have waited for a boat from the guard-ship & that we must pull the whole distance back to the vessel, with the wind dead on end against us & a strong tide running in. During our absence, a boat had come with an officer whom the Captain soon dispatched with a message to his Commander to say ‘He was sorry he was not aware he was entering an uncivilized port, or he would have had his broardside ready for anwering his shot’. When our boats & the health one came alongside, the Captain immediately gave orders to get under weigh & return to M Video. At the same time sending to the Governor, through the Spanish officer, the same messuages [sic] which he had sent to the Guard-ship, adding that the case should be throughily [sic] investigated in other quarters. We then loaded & pointed all the guns on one broadside, & ran down close alongside the guard-ship. Hailed her & said that when we again entered the port, we would be prepared as at present & if she dared to fire a shot we would send our whole broardside into her rotten hulk.* We are now sailing quietly down the river. From M Video the Captain intends writing to Mr Fox & to the Admiral, so that they may take effective steps to prevent our Flag being again insulted in so unprovoked a manner.

The following day, after another tricky passage along the muddy and winding channel of the Rio Plata, with banks often marked by old wrecks – ‘it is an ill wind which blows nobody any good’ said Charles – the Beagle arrived at Monte Video after sunset, and the Captain immediately went on board the Druid. He returned with the news that the Druid would next morning sail for Buenos Aires, and demand an apology for the guard-ship’s conduct. Charles noted belligerently, ‘Oh I hope the Guard-ship will fire a gun at the frigate; if she does, it will be her last day above water.’

A fortnight later the Druid returned from Buenos Aires with a long apology from the government for the insult offered to the Beagle. The captain of the guard-ship had immediately been arrested, and it was left to the British Consul whether he should any longer retain his commission. It seemed nevertheless that the Argentinians had voiced some complaint against FitzRoy’s undiplomatic language, for reporting later to the Hydrographer in London on his conduct of the affair, FitzRoy wrote: