C A V Y. 



7.55 



the upper parts, fading into white on the under. These 

 animals lie concealed in holes of the rock and also in 

 thickets ; but they are met with in the dry and open 

 places, and not in the extensive and close woods. 

 They do not burrow; their food is wholly vegetable ; 

 and they come abroad only in twilight or during the 

 night. There is, therefore, no reason to doubt their 

 being the identical species which present so many 

 varieties of colour in their domesticated state ; and 

 those colours vary so much in different individuals of 

 the same litter, that no one of them can be considered 

 a.-t lie natural colour. We have a similar breaking of 

 colour in the domestic rabbit, although the difference 

 between that animal, in a wild and domestic state 

 within the same country, cannot be as great as the 

 difference between an animal wild in Brazil, and 

 domesticated in Europe. 



Sufficient attention has not been paid to the changes 

 which domestication makes in the colours of animals ; 

 but we have at least something like evidence that 

 the change of colour is, in some degree, in proportion 

 to the change of treatment, including both temper- 

 ature and food. But though it has been hitherto 

 much neglected, this is a point of very great import- 

 ance in the progressive history of animals. It should 

 seem that ground animals, which seek their food in 

 herbage, and corne abroad at twilight or during the 

 night, have all, in their natural state, less or more of 

 an iron-grey tinge in their covering. We cannot 

 suppose that this answers only as a means of conceal- 

 ment from their enemies ; because, though some of 

 them sit on exposed forms, the greater number lurk 

 in concealment during the day, and are abroad in the 

 faint-light. There appears to be some connexion 

 between this shade of colour and the hardihood of 

 the animal, and in proportion as the original colour 

 is departed from, the constitution of the animal seems 

 to be weakened. It is probable also that, in the case 

 of those which are used for food, there is always a 

 falling off in the flavour of the flesh, which accom- 

 panies this breaking down of the colour, and this may 

 be observed by dressing a grey rabbit, and a white or 

 a spotted one exactly in the same manner, and taking 

 cave that their natural flavour is preserved. 



There is one very curious fact in the difference of 

 habit between the tame animal and the wild one, at 

 least if we can implicitly credit the accounts given of 

 the wild animal. In the wild state, the female is 

 described as producing only one at a birth, though 

 the mamma; are the same in number as in the tame 

 one ; and we have already mentioned that the tame 

 sometimes, though not always, produces one for each 

 teat, that is twelve. There is reason to doubt the 

 fact of one only being produced by the wild animal ; 

 because we know of no other case in which a female 

 having numerous teats, and having them both on the 

 breast and the belly, produces only a single young 

 one. Yet the fact is expressly stated by D'Azzara, 

 and has not been contradicted by any other observer. 

 But from the retired habits of these animals, and the 

 places which they frequent, and also the times at 

 which they are abroad, it is not very easy to get an 

 accurate account of their habits as wild. They are 

 much less frequently seen than the burrowing animals, 

 and therefore we are not nearly so well informed 

 respecting them. It is probable, however, that they 

 may be more prolific in a domesticated state than 

 when left in free nature ; and the probability rests 

 upon an analogy which holds very generally both in 



the animal kingdom and the vegetable. In all culti- 

 vated plants, it is in the fruit, or the other portion by 

 which the successional plants are produced, that cul- 

 tivation produces its greatest and most beneficial 

 effects ; and the timber or whatever else constitutes 

 the proper structure of the plant as an individual, 

 may be said, in all cases, to be deteriorated ; and 

 though the quantity of it may be increased, the 

 quality is lowered. It is highly probable that a 

 similar effect is produced by cultivation upon animals; 

 ! and we may suppose that this effect will be great in 

 proportion to their natural fertility, and especially to 

 the shortness of their gestation. This question is, how- 

 ever, one of as much difficulty as that to which we 

 formerly alluded, if, indeed, it is not more difficult; 

 but it is one upon which knowledge is highly desira- 

 ble; and in the case of an animal which appears so 

 docile, that is so obedient to artificial culture as the 

 guinea pig, the tracing of the few hints which we have 

 ventured to throw out on the subject of colour and 

 fertility, would be of far greater importance than those 

 expatiations on the helplessness of the animal which 

 are usually found in the books on natural history. 



THE Moco (Kerodon) is the only other known 

 animal of this curious group. It is rather larger 

 than the guinea pig, and of a greyish olive colour. 

 Its grinding teeth are also differently formed, indi- 

 cating some difference in its food. Each tooth is 

 formed into two triangular prisms, and it is on this 

 account that M. F. Cuvier has given it the name of 

 Kerodon (horned tooth). The habits of this species 

 are but imperfectly known, only they are said to have 

 a considerable resemblance to those of the- guinea 

 pig. It is, however, found in places which are less 

 dry and rocky, though not near the water. Though 

 from the character of their covering, both this and 

 the former species can bear to be wetted without in- 

 jury, neither of them are in the habit of swimming. 



The systematic names which have been given to 

 the other two genera of the group, are not quite so 

 appropriate as this one. Ih/droclucus (water hog) 

 is as objectionable as the common name of guinea 

 pig is in the case of the second one ; and though 

 ancBina (powerless) is expressive of one character of 

 the guinea pig, yet that is not its leading, or even its 

 peculiar character, for there are many other animals 

 equally powerless. 



Those three animals form a very well defined 

 group; and though rodentia are very numerous in 

 South America, these form a distinct section, both in 

 the structure of their teeth and in the places which 

 they inhabit. We have the largest of them inhabit- 

 ing the immediate vicinity of the waters, where the 

 productions of nature are richest, and where tin; 

 largest animals of every natural group and order are 

 to be met with. Then we have the Moco in the in- 

 termediate localities where nature is less productive ; 

 and lastly, we have the guniea pig among the rocks, 

 or in the dry thickets, upon the margins of the arid 

 plains, or of those savannahs which are burnt up with 

 drought at one season of the year and laid unoYr 

 water at another. When we get into places which 

 are more open, the vegetable feeders of South 

 America are still rodentia, and have sometimes been 

 classed in the same group, and even in the same genus, 

 with the animals above noticed ; but a very different 

 structure, or at least power of action, is necessary for 

 animals which seek their food in the dry plains. 

 They are the agoutis, the pacas, the biscaches, and the 



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