208 PRACTICAL HISTOLOGY [XXVII 



projections of the dermis surrounded by epidermis. A 

 thin, fairly homogeneous basement membrane may be 

 seen beneath the epidermis ; it is not always distinct. 



c. The sub-cutaneous connective tissue con- 

 tinuous with and indistinguishable from the deep 

 layer of the dermis. It consists of loose connective 

 tissue, with, usually, masses of fat-cells. 



d. The hairs. Before examining these in the 

 section, take a hair from the head, cut off a small piece, 

 place it in 95 p.c. alcohol containing picric acid, leave 

 a few minutes, wash in strong alcohol, clear and mount. 

 Note in this the outer hyaline cuticle of the hair (here 

 and there yellow stained scales will probably be seen 

 partly detached from it), and the core with longitudinally 

 arranged pigment grains ; possibly also with a central 

 portion, the pith. Turn now to the section, and follow 

 a hair cut longitudinally in its lower part, it expands 

 at the end forming the hair bulb. Note 



The dermis sends the papilla, a bulbous mass with 

 a narrow neck, into the hair bulb. In the epidermis 

 the hair is surrounded by a continuation of the horny 

 layer ; this ceases to be distinct a short way from the 

 surface (a little above the duct of the sebaceous gland). 

 The continuation of the Malpighian layer of the skin 

 outside the hair, the root sheath, stretching down to 

 the hair bulb. 



The cuticle consists of two layers, one attached to the hair, the 

 other to the root sheath. Outside the cuticle, the root sheath consists 

 of two parts, the inner and the outer root sheath. 



The dermic coat of the hair follicle (the depression 

 in the skin in which the hair lies), formed externally of 



