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CHAPTER 6

Rio de Janeiro

On 18 March, after taking further soundings for the chart of the Bay of All Saints, the Beagle sailed slowly out in a light wind, and headed for the Abrolhos, a group of uninhabited islets off the coast of Brazil some 350 miles south of Bahia. Five days later the wind was still light, but there was a sufficient swell to make Charles uncomfortable. Occupation was always the best cure, so he settled down at his microscope to examine a mould called mucor growing on ginger from the steward’s cupboard. He wrote in his notes:

Mucor growing on green ginger: colour yellow, length from 1/20 to 1/15 of an inch. Diameter of stalk .001, of ball at extremity .006. Stalk transparent, cylindrical for about 1/10 of length, near to ball it is flattened, angular & rather broarder:^* Terminal spherule full of grains, .0001 in diameter & sticking together in planes: When placed in water the ball partially burst & sent forth with granules large bubbles of air. A rush of fluid was visible in the stalk or cylinder. If merely breathed on, the spherule expanded itself & three conical semitransparent projections were formed on surface. (Much in the same manner as is seen in Pollen) These cones in a short time visibly were contracted & drawn within the spherule.

Unfortunately the specimen of the mould Mucor (Mucoraceae) was not well preserved, and Henslow wrote to Charles in January 1833 after receiving the first consignment from the Beagle, ‘For goodness sake what is N^o. 223; it looks like the remains of an electric explosion, a mere mass of soot – something very curious I dare say.’

Around the Abrolhos there were shallow rocky shoals stretching far out to the east. One of the tasks allotted to the Beagle by Beaufort was to determine the precise extent of these shoals. FitzRoy therefore steered south-east to the latitude of the Abrolhos, and then turned west, sounding all the time, until a well-defined rocky bank was reached at a roughly constant depth of thirty fathoms. After spending two days surveying parts of the Abrolhos that had not been properly covered by a French expedition under Baron Roussin in 1818–21, perhaps because of the disconcertingly sudden changes in depth called by the French ‘coups de sonde’, two parties landed on 29 March. Charles launched an attack on the rocks and insects and plants, while members of the crew began a much more bloody one on the birds, of which an enormous number were slaughtered. Charles reported to FitzRoy that the rocks, rising to about a hundred feet above the sea in horizontal strata, were of gneiss and sandstone. The general description of the islands entered in his notes was:

The Abrolhos Islands seen from a short distance are of a bright green colour. The vegetation consists of succulent plants & Gramina [grasses], interspersed with a few bushes & Cactuses. Small as my collection of plants is from the Abrolhos I think it contains nearly every species then flowering. Birds of the family of Totipalmes [an old group name for some web-footed sea birds] are exceedingly abundant, such as Gannets, Tropic birds & Frigates. The number of Saurians is perhaps the most surprising thing, almost every stone has its accompanying lizard: Spiders are in great numbers: likewise rats: The bottom of the adjoining sea is thickly covered by enormous brain stones [solitary stony corals similar in appearance to a brain]; many of them could not be less than a yard in diameter.

The Beagle sailed on towards Rio, and on 1 April all hands were busy making fools of one another. The hook was easily baited, and when Lieutenant Sulivan cried out, ‘Darwin, did you ever see a Grampus: Bear a hand then,’ Charles rushed out in a transport of enthusiasm, and was received by a roar of laughter from the whole watch.

Eighty miles from Rio they passed close to the promontory of Cape Frio, where not many years ago gleaming white sand still covered the shore, but today there is a line of skyscrapers. FitzRoy was anxious to revisit the scene where, on the evening of 5 December 1830, the frigate HMS Thetis, bound urgently for England with a cargo of treasure, had been battling desperately against contrary winds and was carried far off course by an unsuspected current, until in strong rain and very poor visibility she had sailed at nine knots directly on to the cliffs at Cape Frio, bringing down all three of her masts and injuring many men. In the subsequent struggles, with waves breaking heavily on the hull, twenty-five members of the crew were lost, and the ship quickly sank. FitzRoy had at one time served as a lieutenant on the Thetis, and concluded his deeply felt account of this tragic accident with the words:

Those who never run any risk; who sail only when the wind is fair; who heave to when approaching land, though perhaps a day’s sail distant; and who even delay the performance of urgent duties until they can be done easily and quite safely; are, doubtless, extremely prudent persons: but rather unlike those officers whose names will never be forgotten while England has a navy.⁵⁸

Arriving at Rio de Janeiro on the evening of 4 April, Charles proudly noted that ‘In most glorious style did the little Beagle enter the port and lower her sails alongside the Flagship … Whilst the Captain was away with the commanding officer, we tacked about the harbor & gained great credit from the manner in which the Beagle was manned & directed.’ As Philip Gidley King remembered it:

Though Mr Darwin knew little or nothing of nautical matters, on one day he volunteered his services to the First Lieutenant. The occasion was when the ship first entered Rio Janeiro. It was decided to make a display of smartness in shortening sail before the numerous men-of-war at the anchorage under the flags of all nations. The ship entered the harbour under every yard of canvas which could be spread upon her yards including studding sails aloft on both sides, the lively sea breeze which brought her in being right aft. Mr Darwin was told to hold to a main royal sheet in each hand and a top mast studding sail tack in his teeth. At the order ‘Shorten Sail’ he was to let go and clap on to any rope he saw was short-handed – this he did and enjoyed the fun of it, afterwards remarking ‘the feat could not have been performed without him’.⁵⁵

In view of the political instability at that period of Brazil and the newly liberated countries on its southern borders, the Royal Navy maintained a squadron of ships at the magnificent harbour of Rio de Janeiro for the general protection of British interests in South America. It was commanded by Admiral Sir Thomas Baker. While Charles was assisting the Beagle so skilfully to shorten sail, the Captain was receiving orders from the Commander-in-Chief for the exact position to be taken up by the Beagle and other ships of the squadron in case marines had to be landed to assist in quelling a mutiny that had broken out among the troops in the town. Fortunately the need did not arise, and all on the Beagle settled down happily to read their accumulated mail from home.

The next morning, Charles landed with the ship’s first official artist Augustus Earle at the Palace steps. Earle had once lived in Rio for some while, and after he had introduced Charles to the centre of the city, they found themselves ‘a most delightful house’ at Botafogo which would provide them with excellent lodgings. Its situation, as painted by Conrad Martens when he was passing through Rio a few months later (Plate 2), was an attractively rural one, but nowadays the shore of Botafogo is regrettably occupied by a sprawling network of multi-lane superhighways. The house was in due course also shared with ‘Miss Fuegia Basket, who’, remarked Charles, ‘daily increases in every direction except height’, with the Sergeant of the ship’s marines, and with young Philip Gidley King, who wrote of it with affection:

At Rio Janeiro Mr Darwin thoroughly enjoyed the new life in a tropical climate. Hiring a cottage at Botafogo, a lovely land-locked bay with a sandy beach of a dazzling whiteness, Mr Darwin took for one of his shore companions the writer, who from having been in the former voyage with his father although then of tender years was able to remember and to recount to the so far inexperienced philosopher his own adventures. “Come King” he would say “you have been round Cape Horn and I have not yet done so, but do not come your traveller’s yarns on me”. One of these was that he had seen whales jump out of the water all but their tails, another that he had seen ostriches swimming in salt water. For disbelieving these statements however, Mr Darwin afterwards made ample reparation. The first was verified one fine afternoon on the East coast of Tierra del Fuego. A large number of whales were around the ship, the Captain, the “Philosopher” and the Surveyors were on the poop, presently Mr Darwin’s arm was seized as a gigantic beast rose three fourths of his huge body out of the water. “Look Sir look! Will you believe me now?” was the exclamation of the hitherto discredited youth. “Yes! anything you tell me in future” was the quick reply of the kind-hearted naturalist.⁵⁵

It was in the Beagle Channel on 28 January 1833 that Charles was thus enlightened:

the day was overpowringly [sic] hot, so much so that our skin was burnt; this is quite a novelty in Tierra del F. The Beagle Channel is here very striking, the view both ways is not intercepted, & to the West extends to the Pacific. So narrow and straight a channell & in length nearly 120 miles, must be a rare phenomenon. We were reminded that it was an arm of the sea by the number of Whales, which were spouting in different directions: the water is so deep that one morning two monstrous whales were swimming within stone throw of the shore.⁵⁹

Charles at once set about organising an expedition on horseback to the Rio Macaé, some one hundred miles to the north-east of Rio. His ‘extraordinary & quixotic set of adventurers’ consisted firstly of an Irish businessman, Patrick Lennon, who had lived in Rio for twenty years and owned an estate near the mouth of the Macaé that he had not previously visited; he was accompanied by a nephew. Then there was Mr Lawrie, ‘a well informed clever Scotchman, selfish unprincipled man, by trade partly slave merchant partly Swindler’, with a friend who was apprentice to a druggist, and whose elder brother’s Brazilian father-in-law Senhor Manuel Figuireda owned a large estate on the Macaé at Socégo. As a guide for the party Charles took along a black boy. The first obstacle was to obtain passports for an excursion to the interior. The local officials were somewhat less than helpful, ‘but the prospect of wild forests tenanted by beautiful birds, Monkeys & Sloths, & Lakes by Cavies & Alligators, will make any naturalist lick the dust even from the foot of a Brazilian’.

The exotic cavalcade set out on 8 April, and Charles was entranced by the stillness of the woods – except for the large and brilliant butterflies which lazily fluttered about, with blue the prevailing tint – and by the infinite numbers of lianas and parasitical plants, whose beautiful flowers struck him as the most novel object to be seen in a tropical forest. In the evening the scene by the dimmed light of the moon was most desolate, with fireflies flitting by and the solitary snipe uttering its plaintive cry while the distant and sullen roar of the sea scarcely broke the quiet of the night. The inn at which they spent their first night sleeping on straw mats was a miserable one, though at others they fared sumptuously with wine and spirits at dinner, coffee in the evening, and fish for breakfast. The five days needed for the journey to the mouth of the Macaé were often strenuous, and the amount of labour that their horses could perform was impressive, even on the occasion when the riders had to swim alongside them to cross the Barro de St João.

On 13 April they rested at Senhor Figuireda’s luxurious fazenda at Socégo, where Charles was relieved to see how kindly the slaves were treated, and how happy they seemed. Two days later he had a very different impression of slavery when Mr Lennon threatened to sell at a public auction an illegitimate mulatto child to whom his agent was much attached, and even to take all the women and children from their husbands to sell them separately at the market in Rio. Despite his feeling that Mr Lennon was not at heart an inhumane person, Charles reflected ruefully on the strange and inexplicable effect that prevailing custom and self-interest might have on a man’s behaviour. It was agreed that Senhor Manuel should be asked to arbitrate in the quarrel, which he presumably did in favour of the slaves, although Charles did not report on the outcome. Charles returned to Socégo, where he spent the most enjoyable part of the whole expedition collecting insects and reptiles in the woods, and admiring the trees:

The forests here are ornamented by one of the most elegant, the Cabbage-Palm, with a stem so narrow that with the two hands it may be clasped, it waves its most elegant head from 30 to 50 feet above the ground. The soft part, from which the leaves spring, affords a most excellent vegetable. The woody creepers, themselves covered by creepers, are of great thickness, varying from 1 to nearly 2 feet in circumference. Many of the older trees present a most curious spectacle, being covered with tresses of a liana, which much resembles bundles of hay. If the eye is turned from the world of foliage above, to the ground, it is attracted by the extreme elegance of the leaves of numberless species of Ferns & Mimosas. Thus it is easy to specify individual objects of admiration; but it is nearly impossible to give an adequate idea of the higher feelings which are excited; wonder, astonishment & sublime devotion fill & elevate the mind.

For the journey home, when Charles was accompanied only by Mr Lennon, the same route was followed, though back in Rio, having carelessly lost their passports, they had some difficulty in proving that their horses were not stolen. Charles returned to the Beagle, where he learnt that the surgeon Robert McCormick had been ‘invalided’, that is to say had quarrelled with the Captain and the First Lieutenant, and was about to go back to England on HMS Tyne. The news did not greatly distress Charles, for he had decided even before leaving Devonport that ‘my friend the Doctor is an ass … at present he is in great tribulation, whether his cabin shall be painted French Grey or a dead white – I hear little excepting this subject from him’. And at St Jago McCormick had revealed himself as ‘a philosopher of rather an antient date; at St Jago by his own account he made general remarks during the first fortnight & collected particular facts during the last’. Robert McCormick was an ambitious Scot, determined to make a career for himself as a naval surgeon, who had sailed to the Arctic in 1827 with William Edward Parry as assistant surgeon on the Hecla. His nose was put thoroughly out of joint on the Beagle by finding that Charles had been introduced by the Captain to look after natural history, one of the traditional responsibilities of the ship’s surgeon. He subsequently sailed to the Antarctic as surgeon on the Erebus, and took part in the search for Franklin in the Arctic in 1852–53. But when he finally retired in 1865, the professional recognition that he had sought for so long still eluded him. He was succeeded as acting surgeon on the Beagle by Benjamin Bynoe, with whom Charles remained on the best of terms for the rest of the voyage.

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 17^th. 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 2^d) 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 28^th. 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.