368 Proceedings of the 



duced by its involution or evolution, it may be that, by draw- 

 ing more of its substance from one layer than from another, 

 the differences in its appearance, which we have been consi- 

 dering, are produced. These are points on which the recent 

 researches of Kolliker, Leydig, Queckett, Inman, and other 

 microscopists have not touched. It is only a skilful histologist 

 who can take them up with any chance of success ; and as I 

 have no pretensions to such a title, I am glad to have enlisted 

 my friend Dr Turner (Demonstrator of Anatomy) in the ex- 

 amination of the subject, and he has undertaken to see if he 

 can throw any further light upon it. 



Another interesting provision with regard to the hair is, 

 that in the rein-deer and the moose or elk (the only two arctic 

 species or families) the part of the muzzle called the muffle, 

 instead of being left bare and moist, as in other ruminants, is 

 clothed with hair — this forming the generic character of the 

 group. A moment's consideration of what the effect would be 

 of plunging a bare and moist muzzle into frozen snow, in the 

 search after lichens, will show how necessary a deviation this 

 is from the normal structure of that part. At first sight one 

 might expect, on like grounds, some analogous deviation from 

 the normal condition of the stomach in arctic animals, but 

 there is none such, and the reason probably is that that organ 

 is not very sensitive, and any special protection to it against 

 the coldness of the food is therefore unnecessary. 



The skin appears to be a good deal cut up before winter by 

 the gad-flies and (Estri, and we have no account how the 

 damage done by these creatures is repaired before the severity 

 of the winter begins to be felt ; doubtless, the sores quickly heal 

 as soon as the originators of the mischief drop out, and the 

 part will only be thicker on account of the healing process ; so 

 that it would be rather curious if the unattacked part of the skin 

 turned out to be in reality the weakest. The hair, too, is cast 

 and replaced at this time, so that the comfort of the animals 

 is sufficiently provided for. 



