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HAND-BOOK OF PHYSIOLOGY. 



and then sometimes again becoming spiral, it passes through the -cuticle 

 and opens by an oblique valve-like aperture. In the parts where the epi- 

 dermis is thin the ducts themselves are thinner and more nearly straight 

 in their course (Fig. 228). The duct, which maintains nearly the same 

 diameter throughout, is lined with a layer of columnar epithelium (Fig. 



FIG. 230. End-bulbs in papillae (magnified) treated with acetic acid. A, from the lips: the white 

 loops in one of them are capillaries. B, from the tongue. Two end-bulbs seen in the midst of the 

 simple papillae: a, a, nerves. (Kolliker.) 



231) continuous with the epidermis; while the part which passes through 

 the epidermis is composed of the latter structure only; the cells which 

 immediately form the boundary of the canal in this part being somewhat 

 differently arranged from those of the adjacent cuticle. 



FIG. 231. Glomeruli of sudoriferous gland, divided in various directions, a, sheath of the gland ; 

 &, columnar epithelial lining of gland tube; c, lumen of tube; d, divided blood-vessel- * loose-con- 

 nective-tissue, forming a capsule to the gland. (Biesiadecki.) 



The sudoriferous glands are abundantly distributed over the whole sur- 

 face of the body; but are especially numerous, as well as very large, in 

 the skin of the palm of the hand, and of the sole of the foot. The glands 



