94 ON THE PIIYSrOGNOMT OF SERPENTS. 



in£^ of the skin during the hybernation. It would be very 

 interesting to know how many moults serpents undergo in 

 warm climates, where the state of sleep does not take place. 

 A state of domesticity, a mode of life little natural to these 

 animals, remarkably influences the functions of the skin, the 

 epidermis of which does not renew itself in fixed and de- 

 terminate periods ; frequently this operation is very long, 

 and so painful tliat the animal suffers much, or it is some 

 times followed by death. In order to reject the old epi- 

 dermis, wliicli begins to detach itself at the head, and espe- 

 cially along tlie borders of the lij>s, the serpent passes it- 

 self through mosses, grasses, or heaths, and contrives, by 

 means of slow and continued movements or frictions, to 

 disengage gradually the exterior layer of the skin, which 

 is already replaced below by a new epidermis. The spoils 

 thus removed are found inverted from one end to the other, 

 forming a sac with a reticulated surface more or less diapha- 

 nous, more wide than the body of the snake, because of the 

 dilatation of the membranous inteiwals, and presenting, 

 \A'ith the exception of those of the mouth and the nostrils, 

 no other orifice than the anus ; for it is well kno^vn that 

 the hemispherical membrane which protects exteriorly the 

 globe of the eye, is part of the integuments, and comes off 

 along with the rejected skin. This skin, at first soft, soon 

 dries, and is easily preserved in cabinets ; but it is rare to 

 find it entire, because it is often torn in the operation we 

 have described. We possess some specimens of several 

 foreign species, which prove that the moulting is produced 

 in the same manner in all serpents. 



The changes which Ophidians undergo, before they iiave 

 acquired their full growth, have been as yet little studied. 

 Thus, sometimes, as we have stated above, the livery of 

 the two sexes presents considerable varieties at different 

 periods of life. The males have often a more thick and 

 longer tail than the females, probably because they have the 

 organs of generation lodged in a cavity at the base of that 

 member ; the females, on the other hand, acquire a size 

 greater than that of the male, and their trunk is then of a 

 more considerable volume. We are entirely ignorant of 

 the age to which the different races of snakes arrive, 



