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But, on the other hand, we must not forget that this same 

 rule which, in the existing races, is observ^ed with respect to 

 those that climb, holds equally good with reference to those 

 that burrow ; which latter faculty is also restricted to the 

 smaller species. Thus, in the genus Canis, foxes and jackals 

 burrow, but not wolves : in the genus Lepus, rabbits bun'ow, 

 but not hares : among the rodents (excluding hares and 

 climbers), all species dig, except the largest of all, the Capi- 

 llar. Must it not, therefore, equally excite our astonishment, 

 to find among the relics of that extinct creation, species of 

 burrowing animals that do not seem to have yielded in size 

 or bulk to the huge climbers of that same period, such as 

 Chlamydotherium Humholdtii, and giganteum, Hoplophorus 

 Euphractus, «&:c. ? And should we have brought the pheno- 

 mena of the economy of that former world more into harmony 

 with the present^ by assigning to those gigantic sloths the fa- 

 culty of hicrrowing^ instead of climbing ? If we examine this 

 creature's habits, we shall find that they, like everything 

 else, speak equally in favour of the latter conclusion. We 

 are acquainted with no single existing animal which feeds on 

 nothing but grass and leaves, that digs or burrows. And for 

 what purpose should these monsters have burrowed ? To pro- 

 tect themselves from their enemies ? Without alluding to the 

 length of time so bulky and helpless a creature must have 

 required to excavate a hole sufficient for its huge carcass, of 

 what use, I will ask, could such a den be for a refuge to an 

 animal, whose food would, of necessity, often call it far away ; 

 and which, in case of danger, was so unsuited to get safely 

 back to it, from its conformation being so ill-adapted for run- 

 ning, nay, as we have seen, even for walking or standing ! 



Should it be contended that Megalonyx had sufficient 

 means of defence in its formidable claws ; I ask, for what 

 purpose then did it burrow ? Certainly not to obtain food, 

 forasmuch as all animals that seek their food underground 

 (which can only consist of insects, frogs, and roots) are ne- 

 cessarily small, and provided with hands, without which con- 

 ditions, the impossibility of their existence in this manner is 

 abundantly evident. Now, what was it that formed the food 

 of these animals ? The fceces of one of these monsters 

 which T have had the opportunity of examining, presented 

 very finely-comminuted remains of plants. May we not 

 then conclude, that they grazed like cattle and some Pachy- 

 dermata f I answer, we find no incisors in the fore-part of 

 the mouth, wherewith they could bite grass. Hence we are 

 forced to conclude that they fed on leaves of trees, like their 

 existing representatives, which they exactly resemble in their 



