180 Proceedings of the 



The process of sloughing is very interesting. Eight days 

 usually, but from eight to ten days, before an animal throws 

 off its scaly covering, it assumes a peculiar opaqueness, and 

 seems less active. On the fourth or fifth day the original 

 colour is gradually regained, but with less of brightness, and 

 perhaps of a darker shade. On examination about the eighth 

 day, the scales will no longer be found attached to the scale- 

 plates, and the creature is restless. It rubs its head on the 

 grass in the bottom, or on the sides of its box, first on one 

 side, and then on the other, with the evident object of detach- 

 ing the jaw scales, which it ultimately effects ; and so soon 

 as this is the case, the rest of the process may be, and is, per- 

 formed with apparent ease by muscular action entirely. The 

 scales of the upper jaw being thrown up, and those of the lower 

 jaw down, the head is jerked from side to side till the scales 

 are relieved. A peculiar vermicular action of the body is in- 

 stituted and kept up, every movement having the effect of 

 gradually sliding the scales back upon each other. But this 

 action does not seem to be entirely local, or directed in such 

 a way as to remove the scales by gradation from the head 

 backwards only, for the action is simultaneous throughout the 

 entire length of the animal. The scales covering the cloacal 

 valve are often carried, by the action alluded to, perhaps an 

 inch backward — by extension — before the head scales are even 

 free; and the scales of the extreme part of the tail are already, 

 it may be, detached from the animal to the extent of from one 

 to two and a half inches, when the upwrinkled slough reaches 

 the extremity. An example of sloughing, which, in one well-ob- 

 served instance, began at the head and cloaca at the same time 

 (from the scales giving way and separating at that point), 

 more clearly illustrates the peculiar action, for each portion 

 moved backward, as if each had been an independent slough. 



The time occupied in sloughing, — that is, from the moment 

 the scales become detached from the head till thrown off, — oc- 

 cupies variously from one to two and a half hours ; but with 

 assistance, or, perhaps, with such aids as the animal might 

 seek in a state of freedom, the process may be very quickly 

 completed. So soon as the head scales are free, if the animal 



