NUTRITION OF HAIR. 



301 



The simplest examples that can be adduced of this are in 

 the hair and teeth ; and it may be observed, that, in the pro- 

 cess which will now be described, all the great features of the 

 process of nutrition seem to be represented. 1 



An eyelash which naturally falls, or which can be drawn 

 out without pain, is one that has lived its natural time, and 

 has died, and been separated from the living parts. In its 

 bulb such a one will be found different from those that are 



Intended to represent the changes undergone by a hair towards the close of its 

 period of existence. At A, its activity of growth is diminishing, as shown by the 

 small quantity of pigment contained in the cells of the pulp, and by the interrupted 

 line of dark medullary substance. At B, provision is being made for the formation 

 of a new hair, by the growth of a new pulp connected with the pulp or capsule of 

 the old hair. c. A hair at the end of its period of life, deprived of its sheath and of 

 the mass of cells composing the pulp of a living hair. 



still living in any period of their age. In the early period of 

 the growth of a dark eyelash, the medullary substance appears 

 like an interior cylinder of darker granular substance, con- 



1 These and other instances are related more in detail in Mr. 

 Paget's Lectures on Surgical Pathology, from which this chapter was 

 originally written. 



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