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epithelium, softened by perspiration, fills up the crevices, and before it 

 has had time to harden, another accumulation takes place, and so on until 

 the whole hair is often covered with a dense coat. This makes the 

 axillary hairs appear coarser than any others, and rougher to the feel. They 

 may however readily be cleaned by passing through the finger. These 

 present no other peculiarity beyond their palpably fibrous character. 



I am aware that another explanation may be given of this appearance, 

 namely, that it arises from an exudation of the cement which binds the 

 fibres together, that it is a sort of haemorrhage like that which takes 

 place in a tree when its bark has been cut through. 



This view is important, as it bears upon the doctrine of the great or 

 small vitality of the hair. I do not adopt it, for the following reasons : 

 first, hairs cut elsewhere do not exude any cement or fluid substance ; 

 secondly, this deposit is occasionally in layers, but is never uniform 

 the whole length of the hair ; thirdly, it is absent where two hairs are 

 in contact ; fourthly, it is most abundant at the extremity of the hair, 

 where the probability of any exudation is the smallest. 



I have met with oue instance in which the whiskei*s of a gentleman, 

 naturally black, appeared as if powdered with white. This arose from a 

 natural cracking of the hair half way across, and a separation of its 

 fibres; each of these refracted the light, and so gave it the appearance 

 of a white patch. 



The medulla of the hair consists of an irregular row of cells occu- 

 pying the centre of the hair, and continuous with the mucous layer of 

 the follicle. It is met with in almost all hairs, such as the human, &c. 

 It is not to be confounded with the cellular interior of other hairs, such 

 as the rat's, deer, &c. Its normal character is that of a number of cells 

 superimposed on each other like a row of coins. Occasionally, no 

 division into cells can be traced, owing to absorption of the contiguous 

 cell walls. It may be seen equally at the top of the hair and at the 

 bulb, from which it takes its origin. Its intention is evidently to supply 

 a nutritious material to the rest of the hair. It appears to be absent in 

 cellular hairs, as may be proved by an inspection of the roots. In them 

 it is replaced by the expansion of the fibrous tissue. This cellular 

 expansion commences at a short distance from the surface of the skin, 

 and varies according to the size of the hair and the class of the animal. 

 The simplest form is in the fur of the rabbit, and where the cells are 

 rectangular and arranged in a linear direction. In the hare, they are 

 still rectangular, but arranged in many rows, and occasionally uniting. 

 In the deer, they are so numerous as to occupy the whole of the body 

 of the hair, and so irregular that no particular place of subdivision can 

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