126 PRACTICAL HISTOLOGY. 



the horny layer above. The lower stratum of the latter is 

 clear and almost homogeneous in appearance. 



In the cutis vera observe the papillae, the areolar tissue, 

 sudoriferous ducts ; probably the coils of the ducts and 

 fat cells will be found in the deeper stratum. 



(H.) The epidermic cells have already been examined 

 ( 87), but it will be well to complete the subject by looking 

 at the clear layer at the junction of the horny layer with 

 the rete mucosum, sometimes spoken of as the layer of 

 Langerhans. It consists of epidermic cells so condensed 

 that it is scarcely possible to see their outlines, unless the 

 section be stained with such a dye as picro-carmine. 



The papilla consist of a compact fibrous tissue. Deeper 

 in the cutis the tissue becomes distinctly areolar. 



The sweat glands are simple tubules that will probably 

 be found cut in various directions. In the cutis there is a 

 basement membrane lined by the gland cells. In the 

 cuticle the sweat canal is an irregular somewhat twisted 

 channel amidst the epidermic cells. 



A touch corpuscle may be found in a papilla here and 

 there, somewhat oval in shape, and having a fibrous appear- 

 ance. A nerve fibre may, perhaps, be seen in connection 

 with it. (The nerve fibre passes to the summit, and then 

 ends within the corpuscle in a soft core that is enclosed in 

 a tunic of fibrous tissue. This, however, can only be seen 

 when the corpuscle has been rendered very transparent, 

 eg., by acetic acid.) 



Pacinian corpuscles may possibly be found in the lower 

 part of the cutis (seeing that the skin under examination 

 is from the palmar surface of the finger). The structure of 

 these has been already considered ( 159). 



225. Examine (L.) V. S. skin of human heel. The 

 sudoriferous glands may be very distinctly seen in this 

 situation. 



226. Examine (600 diam.) a tactile corpuscle in an 

 extremely thin V. S. of skin from palmar surface of point 

 of human finger. 



227. Human Hair. (H.) Pluck out a hair of the 

 head with its bulb, if possible ; place a drop of dammar 



