HIBERNATION AND SLOUGHING. 67 
chemical secretion by the vital activity peculiar to 
that particular gland. Surely when all the other 
glands and organs in the body are practically at a 
standstill, one can hardly believe that the poison- 
gland goes on secreting just the same, independently 
of the circulation and other body functions. In this 
country most observers agree that the adder bite 
during hibernation is comparatively innocuous, and this 
conclusion is what one would expect from theoretical 
reasoning on the physiological condition of the reptile 
during that period of general functional inactivity. 
Sloughing.—The process of sloughing in serpents 
is the periodical casting-off of the external epidermic 
covering. “This moulting of the skin is effected by 
its being pushed off by the upward growth of fine, 
temporary cuticular hairs. On certain parts of the 
body, as on the under side of the capsular skin and 
scales of the eyes, these hairs do not develop. After 
the skin is loosened it dries and is readily shuffled 
off’! It is sometimes stated that the sloughing is an 
annual process, but I think most observers are now 
agreed that our snakes cast their slough several times 
every year. The slough, once cast, is said to be used 
as an article of diet in some species, but I am inclined 
to think that is more commonly the habit of amphib- 
lans than serpents, though perhaps the latter also do 
it. M. C. Cooke expressly states that in the case of 
the ring snake the slough is left on the grass, and I 
1 Packard. 
