274 ELEMENTS OF HISTOLOGY, [chap, xxxiv. 



stated above, by a thin albuminous envelope Ascher- 

 son's membrane. The small bits of granular substance 

 met with here and there, are probably the remains of 

 broken-down protoplasm of epithelial cells. 



368. Each gland alveolus is surrounded by a dense 

 network of capillary blood-vessels. The alveoli are 

 surrounded by lymph spaces like those in the salivary 

 glands (Coyne) and these spaces lead into networks of 

 lymphatic vessels of the interlobular connective tissue. 



CHAPTER XXXIV. 



THE SKIN. 



369. THE skin consists of the following layers 

 (Fig. 145): (1) the epidermis; (2) the corium, or 

 cutis vera, with the papillae; (3) the subcutaneous 

 tissue, with the adipose layer or the adipose tissue. 



370. (1) The epidermis (Fig. 14), in all its 

 constituent elements, has been minutely described in 

 Chapter III. Its thickness varies in different parts, 

 and is chiefly dependent on the variable thickness of 

 the stratum corneum. This is of great thickness in 

 the palm of the hand and the sole of the foot. The 

 stratum Malpighii fits into the depressions between 

 the papillae of the corium as the interpapillary pro- 

 cesses. The presence of prickle cells, of pigment 

 granules, and of branched interstitial nucleated cells, 

 &c., has been mentioned in Chapter III. 



There occur in the stratum Malpighii migratory 

 cells of granular aspect ; they appear to migrate from 

 the papillary layer of the corium into the stratum 

 Malpighii (Biesiadecki). 



371. (2) The corium is a dense feltwork of 

 bundles of fibrous connective tissue, with a large 



