HIBERNATION AND SLOUGHING. 69 



folded backwards over the body, ultimately being 

 left turned inside out. An interesting object is the 

 eye-covering, which is shed along with the rest of the 

 slough, and is seen to be a thick transparent scale, 

 very like an ordinary watch-glass. The accompanying 

 drawing (see opposite page) is from an adder which 

 was sloughing when I captured her. I reproduce it 

 as seen under the low power of the microscope. It 

 is seen to be surrounded by scales of various sizes, in 

 this case ten in number. The scales have a granular 

 appearance, while the eye-scale is transparent. 



In Coronella avMriaca, the smooth snake, the slough- 

 ing was very carefully observed by Dr Opel in the 

 specimen he secured in Silesia. He found that this 

 snake cast its slough monthly in June, July, and 

 August, and has no doubt that in its natural con- 

 dition the first casting would be in April, after the 

 winter hibernation. This snake was in captivity 

 during these observations, and it seems that, follow- 

 ing upon the completion of the process, the reptile 

 displayed unwonted energy and excitement. 



My own observations on sloughing have been con- 

 fined to our adders, and after watching them very 

 carefully for some years, I find the process in them 

 varies somewhat from the accounts usually given of 

 the sloughing in the ring snake. (Miss Hopley, de- 

 scribing the sloughing of the Ophidia generally, says : 

 " If a snake is in good health and sheds well, the 

 whole process does not occupy many minutes ; but if 



