250 SKIN, HAIR, AND NAILS, BY ALFRED BIESIADEOKI. 



These two layers of cuticle are firmly attached to each 

 other ; for, on tearing out a growing hair, both, as a rule come 

 away, together with the inner root-sheath of the hair, and it is 

 only in rare instances that the hair alone is pulled out with 

 the inferiorly covered scales of the hair cuticle. 



At the level of the papilla the external cells of the peripheric 

 portion of the hair root become elongated in the direction of 

 the long axis of the hair into fusiform cells, the lower ones 

 becoming filled with a few, the upper with numerous, highly 

 refractile granules, that usually conceal the shrunken nucleus. 



In the lower part of the hair follicle these cells are in contact 

 with the vitreous membrane ; and higher up, with the internal 

 root-sheath of Henle, already described, which is composed of 

 fusiform, but non-nucleated, epidermic cells. 



The former, or deeper cells, are distinguished from the latter 

 by the circumstance that a nucleus is still visible in their 

 interior, and that they are filled with highly refractile granules, 

 which become only feebly tinted with carmine, whilst the others 

 are destitute of nuclei, and do not stain with carmine at all. 



The most external cells of the hair root constitute a special 

 sheath to the hair, which, having been first described by 

 Huxley, is termed the sheath of Huxley. At the level at 

 which the hair is still composed of distinct nucleated and soft 

 cells, that easily stain with carmine, this sheath consists of 

 nucleated fusiform cells, filled with small refractile granules ; 

 but above this level the cells are destitute of nuclei, and form 

 a sheath that, in consequence of the fusion of the contained 

 granules, appears homogeneous in longitudinal section, and 

 similar to the vitreous layer, and coalesces with the internal 

 root-sheath of Henle to form the single internal root-sheath 

 of authors. 



This internal root-sheath formed by the coalescence of the 

 inner root-sheath of Henle with Huxley's sheath, reaches as 

 far as to the neck of the hair follicle, where, according to the 

 statements of most anatomists, it terminates by undergoing 

 fibrillation. Well-prepared longitudinal sections, however, show 

 that the internal root-sheath, becoming considerably attenuated, 

 is continued along the neck of the hair follicle. Its scales 

 become suddenly flattened at the beginning of the neck of the 



