EPIDERMAL APPENDAGES. 329 



forming a capsule which is moulted with the cuticle. 

 Physiologists tell us that it is moistened with the lachrymal 

 fluid. Bright and glistening is the serpent's eye, except 

 previous to desquamation, when, from the new skin forming 

 beneath, it becomes opaque and dull, and the snake is 

 blind for a few days more or less, according to its health at 

 the time. Rymer Jones considers the transparent mem- 

 brane cast with the slough a real eyelid in a framework of 

 regular scales ; Huxley (in the lecture already alluded to) said 

 snakes' eyelids are as if our two eyelids were joined. In form 

 and appearance this moulted cuticle 

 is singularly clear and shapely : on 

 the outer side, like a miniature watch- 

 glass ; but within it is a perfect cup, H'-^tration of eye covering. 



standing up and out from the surrounding scales like a 

 cup in a saucer, the rounded base of which is the transparent 

 skin, as here seen. 



For the process of sloughing or casting the skin, the term 

 desquamation — literally, an unsealing — is often used ; but 

 this word seems rather to imply an unhealthy action, as 

 if the cuticle peels off in pieces, than the normal operation, 

 which is to shed it entire. 



It is a matter of surprise — if we are to believe what we 

 read — that few naturalists seem to have witnessed this 

 process, so as to be able to describe it from their own 

 observations ; but this must be due more to lack of interest 

 than of opportunity, since the occurrence is very frequent. 

 Those in the vicinity of Zoological Gardens have no excuse 

 for not observing it ; yet so lately as Oct. 1879, we find a 

 writer in Nature, vol. xx. p. 530, attempting to describe the 



