284 



THE ORGANS 



and large. The connective tissue of the gland contains many 

 lymphoid cells (Fig. 185). 



Near the sublingual gland is a group of some 5 to 20 simple 

 tubular glands. Their terminal tubules are hned almost wholly with 

 mucous cells. This group of tubules has been designated the "sub- 

 ungualis minor." 



The submaxillary gland is also a mixed gland in man, dog, cat, 

 and rabbit. In complexity of its duct system it stands between the 

 parotid and the sublingual (Fig. 182). The main duct (Wharton's) 

 has not only a two-layered epithelial lining resting upon a basement 



Fig. 185. — Section of Human Sublingual Gland. X252. (Stohr.) a, Excretory 

 duct; b, lumina of serous and mucous tubules; c, mucous tubule; d, demilune; e, serous 

 tubule;/, cross section mucous tubule; g, interstitial connective tissue. 



membrane, but is distinguished by a richly cellular stroma and a 

 thin layer of longitudinally disposed smooth muscle. Branches of the 

 main duct open into long secreting tubules which communicate with the 

 terminal tubules by means of short narrow intermediate tubules (Fig. 

 1 8 2 C) . The secretory tubules are lined as in the parotid with columnar 

 cells whose bases are longitudinally striated. These cells usually con- 

 tain more or less yellow pigment. The intermediate tubules have a 

 low cuboidal or flat epithelium. Most of the end tubules contain 

 serous cells only (page 226). The crescents of the mucous tubules 

 (page 227) are less numerous and smaller than those in the sublingual, 

 consisting as a rule of only from one to three cells (Fig. 186). They 



