HO 



THIRTEENTH LECTURE. 



denhain). Its cells differ in the several animals. The former 

 are granular in the rabbit. In the dog and cat, on the con- 

 trary, we find a mucous gland. 



The cells (Fig. 131) here consist of two different structures. 

 Firstly (a), we meet with large rounded elements, which are 



filled with a homogeneous 

 mucous substance. Be- 

 sides these, quite granular, 

 smaller cells occur in the 

 periphery of the gland 

 vesicle (c). Pressed closely 

 together, and indistinctly 

 separated from each other, 

 they form a sort of cres- 

 cent (Gianuzzi). They 

 subsequently change into 

 those large mucous cells. 

 The finest secretory capil- 

 laries, after the manner of 

 our Fig. 125, likewise 

 make their appearance 

 here, as also do the flat 

 stellate cells of the membrana propria (see Fig. 118). The 

 excretory ducts show cylinder cells (Fig. 131, d), with longi- 

 tudinal striations beneath the nucleus. We have, finally, to 

 mention a rounded capillary reticulum, and abundant lym- 

 phatics around and between the lobules and lobes. 



The sublingual appears to be nearly related to the sub- 

 maxillary gland. 



We cannot, however, yet leave the latter. As experimen- 

 tal physiology teaches, the irritation of the chorda tympani 

 produces a profuse watery secretion ; that of the sympa- 

 thetic, on the contrary, a scanty quantity of a thick fluid 

 substance. 



The continued irritation of the nerves, as Heidenhain ascer- 

 tained, produces an important change in the contents of the 

 acini (Fig. 132). Nearly all the large round cells (a) have, 



Fig. 131. — The submaxillary g'and of the dog ; 

 a, mucous cells ; 6, protoplasma cells ; c, crescent : 

 d, transverse section of an excretory duct, with the 

 peculiar cylindrical epithelium. 



