IIBERNATION 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 austriaca, 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: 
“Tf a snake is in good health and sheds well, the 
whole process does not occupy many minutes ; but if 
