306 



MUSEUM OF ANIMATED NATURE. 



[Land-cuabs. 



cation : nevertheless it is essential that the branc-hie 

 be always kept moist, for death equally results from 

 the desiccation of these organs. We have pre- 

 viously alluded to the size of the branchial cavity 

 in the Ocypodians, and in the present tribe the same 

 confirmation exist*. This cavity on each side is 

 not only very ample, being raised into a vault highly 

 elevated above the branchi», but the tegumentary 

 membrane which lines it is also very spongy, and 

 is orten disposed into a sort of fold along the lower 

 edge of the cavity, so a» to form a gutter or longi- 

 tudinal trough for containing water when the animal 

 remains exposed to the air. It has been shown by 

 MM. Milne Edwards and Audouin (' De la Respira- 

 tion aiiiienne des Crustaci-s, et dcs modifications que 

 I'appareil branchial eprouve dans les Crabes ter- ^ 

 resties';, that in all the Crustacea the branchise are 

 fitted to perform the functions of respiratory organs 

 in the air as well as in the water; that the more or less 

 rapid death of the aquatic species when exposed to 

 the air depends upon various causes, of which one 

 of the most direct is the evaporation from the bran- 

 chiae, and that, consequently, one of the conditions 

 necessary to the support of life in animals which 

 have branchise and live in the air, is that these 

 organs be kept moist, and always defended from 

 desiccation. In the land-crabs these arrangements 

 and provisions are proved actually to occur. They 

 possess various organs destined for absorbing and 

 keeping in reserve the quantity of moisture neces- 

 sary for supplying the branchiae with a due pro- 

 portion of fluid : in fact, for maintaining them in 

 working condition. 



The land-crabs are distributed through the 

 warmer regions of the Old and New World, and 

 Australasia, but the species are most numerous in 

 America and its islands. In their descriptions, 

 however, of the habits of these animals, the writers 

 who supply us with the most interesting details, 

 viz., De Labat, Sloane, Brown, Hughes, Catesby, &c. 

 (' Nouveau Voyage aux Isles d'Am6rique ;' ' Natural 

 History of Jamaica ; ' ' Civil and Natural History of 

 Jamaica ;' 'Natural History of Barbadoes ; ' ' Natural 

 History of Carolina '), seldom attend to the particular 

 species, or enable us positively to identify that to 

 which their details immediately refer. All the 

 Gecarcinians, however, live mure or less inland, 

 paying at stated periods a short visit to the sea, the 

 females for the purpose of disencumbering them- 

 selves of the eggs, which are carried under the ab- 

 domen. On land they dwell in burrows, where they 

 undergo the process of exuviation. Their history, 

 says Latreille, in Cuvier's 'Regne Animal,' may be 

 summed up as follows :— " They pass the greatest 

 part of their life on land, hiding in burrows, whence 

 they issue forth in the evening ; some take up their 

 abode in graveyards. Once a year, when they would 

 lay their eggs, they assemble in numerous troops, 

 and take the shortest course to the sea, without 

 being deterred by any obstacles which they may 

 meet with on the road. After the deposition of the 

 eggs, they return in a state of great debility. During 

 the season of exuviation they block up, as is stated, 

 the mouths of their burrows; whilst undergoing 

 this process, and still soft, they are termed ' bour- 

 siers,' or Purse-crabs, and their flesh is then held 

 in high estimation; nevertheless it is sometimes 

 deleterious. This quality is attributed to the 

 fruit of the manchineel (mancenillier), of which it is 

 supposed, perhaps without foundation, that they 

 have eaten." 



We may here remark that these Boursiers, or land- 

 crabs in a state of moult, and covered only by a soft 

 membrane, must not be confounded with the Birgus 

 Latro, or Robber Crab, a native of Amboyna, called 

 by Humphius Cancer crumentatus, or Purse-crab, 

 from its shape. It was from a confusion occasioned 

 by this name of " Purse-crab," that Linnaeus assigned 

 the Antilles as well as Amboyna as the locality of 

 Birgus Latro (Cancer Latro). He gives Rochefort 

 (' Hist. Nat. et Morale des Isles Antilles de I'Ame- 

 rique," 4to., Rotterdam, 1681) as his authority, but 

 the purse-crabs to which Rochefort alludes are the 

 " Crabes peintes " during their state of moult. His 

 words are:— What is most remarkable in these 

 crabs is, that once a year, namely, after their return 

 from their seaward journey, they all hide themselves 

 in the ground for about six weeks, so that not one 

 is to be seen. During this time they change their 

 skin or shell, and entirely renew themselves. At 

 this juncture they so neatly close the mouths of 

 their burrows with earth, that no opening is per- 

 ceptible; this they do to exclude the air, for when 

 they thus cast off their old garment, their whole 

 body is, as it were, naked, being only invested 

 with a tender and delicate pellicle, which by 

 degrees thickens and hardens into a crust, ac- 

 cording in solidity to that which they have quitted. 

 M. du Montel states that he has purposely directed 

 the places to be dug up in which there was the 

 appearance of these animals being concealed ; and 

 having, in fact, found them, he remarked that 

 they were enveloped in leaves, which, doubtless, 



served them both for food and a nest during 

 their retirement, but they were so languishing, 

 and so incapable of supporting the fresh air, that 

 they appeared half dead, though otherwise they 

 were fat and very dehcate eating. The inhabitants 

 of the islands call them at that season "Crabes 

 boursidres," purse-crabs, and greatly esteem them. 

 Close to them he found their old slough, that is, 

 their shell, which appeared as perfect as if the ani- 

 mal were still within it; and strange it is that, 

 although he used good eyes, scarcely could he dis- 

 cover the opening or slit whence the body of the 

 creature had emerged, and became freed from that 

 prison. However, after very careful scrutiny, he 

 remarked in these sloughs a little separation at the 

 side of the tail, through which the crabs had extri- 

 cated themselves. 



To return to the asserted poisonous quality of 

 these crabs; though, perhaps, it may be attributed 

 to a wrong cause, the fact itself is noticed by many 

 writers. Sloane (' Nat. Hist, of Jamaica') observes 

 that they are accounted poisonous when they feed 

 on the mansanilla tree, which he thinks may arise 

 from portions adhering about the mouth, or remain- 

 ing still undigested in their stomach. Catesby, who 

 says that some of these crabs are black, some yellow, 

 some red, others variegated with yellow, white, and 

 red, states that the black kind, in particular, are 

 often noxious, and that the light-coloured kind are 

 reckoned the best ; when in full flesh, very well 

 tasted. He adds that they feed on vegetables. 

 Hughes observes that the large white crab feeds on 

 vegetables, and likewise upon manchineel apples, 

 and the leaves and berries of poison-trees, and that 

 after the latter food it is not to be eaten with 

 safety. 



M. Milne Edwards in his account of these singular 

 crabs remarks that they ordinarily haunt humid 

 places, and hide themselves in burrows, which they 

 excavate in the earth : each species, however, has 

 its peculiar locality. Some, for example, live in 

 the low marshy lands near the sea, others on the 

 wooded hills at a distance fjom the shore. At 

 certain epochs these last quit their habitual dwell- 

 ings and journey to the sea ; it is, indeed, reported 

 that they unite in great bands, and thus make way 

 unimpeded by any obstacle, and laying waste 

 everything in their course. Their principal food 

 consists of vegetable substances, which they wander 

 to procure during the hours of darkness ; and in the 

 rainy season in particular quit their burrows, and 

 may be seen running along with great rapidity. 

 It would appear that at the time of laying they go 

 to the sea, and there deposit their eggs, but, he 

 adds, we have no decided information on this point. 

 During their moult they remain hidden in their 

 burrows. 



In our introductory observations on the Crustacea, 

 we stated that, according to Mr. Thompson, the 

 young undergo certain transformations before as- 

 suming their permanent form. It was on the eggs, 

 and young just hatched, of one of the West Indian 

 Gecarcinians, in the collection of the late Rev. 

 Lansdown Guilding, that Mr. Westwood made his 

 observations (published in the 'Phil. Trans.,' 1835), 

 proving that, in the species at least which he ex- 

 amined, no such metamorphosis takes place. 



The first genus to be noticed of this tribe is that 

 termed U^a by Latreille. One species U9a Una 

 (Cancer cordatus and Cancer U?a, Linn.), is repre- 

 sented at Fig. 3142. It inhabits the marshy grounds 

 of Guiana and Brazil. The claw-limbs are spiny ; 

 the other limbs hairy below. Its manners are not 

 well known. 



Another genus is termed Cardisoma ; to this be- 

 long the white crabs of the Antilles, so called in 

 contradistinction to the dark or black, for the shell 

 is yellowish with stains of red. The species give 

 preference to woods, digging deep holes, and wan- 

 dering abroad at night. As an example we refer to 

 Cardisoma carnifex. Fig. 3143. This crab is found 

 in the neighbourhood of Pondicherry. We know 

 not whether it is to this genus or not that a sin- 

 gular land-crab belongs observed in India by the 

 late Bishop Heber, living, to his surprise, a great 

 distance from the sea. "The plain of Poonah," he 

 says, " is very bare of trees, and though there are 

 some gardens immediately around the city, yet as 

 both these and the city itself lie in a small hollow 

 on the banks of the river Moola, they are not suf- 

 ficiently conspicuous to interrupt the general cha- 

 racter of nakedness in the picture, any more than 

 the few young trees and ornamented shrubs with 

 which the bungalows of the cantonment are inter- 

 mingled. The principal and most pleasing feature 

 is a small hill immediately over the town, with a 

 temple of the goddess Parvation its summit, and a 

 large tank, which, when I saw it, was neariy dry at 

 its base. All the grass-land round this tank, and 

 generally through the Deccan, swarms with a small 

 land-crab, which burrows in the ground, and runs 

 with considerable swiftness, even when encumbered 

 with a bundle of food almost as big as itself. This 



food is grass, or the green stalks of rice : and it 

 is amusing to see them sitting, as it were upright, 

 to cut their hay with their sharp pincers, then 

 waddling oif with the sheaf to their holes, as fast 

 as their sidelong pace will carry them." Instead 

 of going to the sea in order to deposit their eggs, 

 may not these crabs resort to the tanks and rivers 

 of the country, and may not the species belong to 

 the fluviatile Thelphusians? Of this group, in- 

 deed, Leschenault discovered a species in the moun- 

 tains of Ceylon ; and another, the Cancer senex'of 

 Herbert, also inhabits the East Indies. If, however, 

 this little crab be a true Gecarcinian, we see no 

 reason why it should not be a visitant to fresh 

 instead of saline waters. 



We pass to the restricted genus Gecarciniis, of 

 which the Black or Mountain crab, the Violet crab, 

 or Toulourou, Gecarcinus ruricola, Fig. 3144, is an 

 example. 



'•These creatures," says Brown ('Civil and 

 Natural History of Jamaica') " are very numerous 

 in some parts of Jamaica, as well as in the neigh- 

 bouring islands, and on the coast of the main con- 

 tinent ; they are generally of a dark purple colour, 

 but this often varies, and you frequently find them 

 spotted, or entirely of another hue. They live 

 chiefly on dry land, and at a considerable distance 

 from the sea, which, however, they visit once a 

 year to wash off their spawn, and afterwards return 

 to the woods and higher lands, where they con- 

 tinue for the remaining part of the season ; nor do 

 the young ones ever fail to follow them as soon 

 as they are able to crawl. The old crabs gene- 

 rally regain their habitations in the mountains, 

 which are seldom within less than a mile and not 

 often above three from the shore, by the latter end 

 of June, and then provide themselves with conve- 

 nient burrows, in which they pass the greatest part 

 of the day, going out only at night to feed. In 

 December and January they begin to be in spawn, 

 and are then very fat and delicate, but continue to 

 grow richer until the month of May, which is the 

 season for them to wash oft' their eggs. They 

 begin to move down in February, and are very 

 much abroad in March and April, which seems to 

 be the time for the impregnation of their eggs ; the 

 males about this time begin to lose their flavour 

 and richness of their juices. The eggs as they 

 pass are entangled in the branchial capillaments, 

 with which the under side of the apron is copiously 

 supplied, to which they stick by the means of their 

 proper gluten, until the creatures reach the surf, 

 where they wash them all olF, and then thev begin 

 to return back again to the mountains. It is re- 

 markable that the bag or stomach* of this creature 

 changes its juices with the state of the body ; and 

 while poor is full of a black, bitter, disagreeable 

 fluid, which diminishes as it I'altens, and at length 

 acquires a delicate rich flavour. About the month 

 of July or August the crabs fatten again and prepare 

 for mouldering, filling up their burrows with dry 

 grass, leaves, and abundance of other materials : 

 when the proper period comes, each retires to his 

 hole, shuts up the passage, and remains quite inac- 

 tive until he gets rid of his old shell and is fully 

 provided with a new one. How long they continue 

 in this state is uncertain, but the shell is observed 

 to burst both at the back and sides to give a pass- 

 age to the body, and it extracts its limbs from all 

 the other parts gradually afterward. At this time 

 the fish is in the richest state, and covered only with 

 a tender membranous skin, variegated with a multi- 

 tude of reddish veins ; but this hardens gradually 

 after, and becomes soon a perfect shell like the 

 former ; it is, however, remarkable that during this 

 change there are some stony concretions always 

 formed in the bag, which waste and dissolve gra- 

 dually as the creature forms and perfects its new 

 crust. A wonderful mechanism ! This crab runs 

 very fast, and always endeavours to get into some 

 hole or crevice on the approach of danger ; nor does 

 it wholly depend on its art and swiftness, for while 

 it retreats it keeps both claws expanded, ready to 

 catch the oft'ender if he should come within its 

 reach, and if it succeeds on these occasions it com- 

 monly throws off the claw, which continues to 

 squeeze with incredible force for near a minute after ; 

 while he, regardless of the loss, endeavours to make 

 his escape and to gain a more secure or a more 

 lonely covert, contented to renew his limb with his 

 coat at the ensuing change ; nor would it grudge to 

 lose many of the others to preserve the trunk entire, 

 though each comes off' with more labour and re- 

 luctance as their numbers lessen." 



As an article of food this species is highly prized 

 in the West Indies, and consequently in great de- 

 mand. Brown says that the black crab, when fat, 

 and in a perfect state, surpasses everything of the 

 sort in flavour and delicacy; it frequently joins a 

 little of the bitter with its native richness, which 

 renders it not only more agreeable in general, but 

 makes it sit extremely easy upon the stomach, 



• Query — Is the liver not meant here ? 



