chap, xxii.] THE SALIVARY GLANDS. 



179 



glands, such as the parotid of man and mammals, 

 the sub-maxillary and orbital of rabbit, the sub- 

 maxillary of the guinea-pig. They secrete true, thin, 

 watery saliva. 



(2) Mucous glands, such as the sub-maxillary and 

 orbital of cat and dog (Fig. 107), the sub-lingual 







Fig. 107. From a Section through the Orbital (mucous) Gland 

 of Dog. Quiescent state. 



The alveoli are lined with transparent " raucous cells," and outside 

 these are the demilunes of Heidenhain. (Heidenhain.) 



of cat, dog, rabbit, and guinea-pig. They secrete 

 thickish, less watery mucus. 



(3) Mixed salivary, or muco -salivary glands, such as 

 the sub-maxillary and sub-lingual of man and ape. 



In addition to the three salivary glands parotid, 

 sub-maxillary, and sub-lingual there are in some 

 cases, as in the rabbit and the guinea-pig, two minute 

 additional glands, one intimately annexed to the 

 parotid and the other to the sub-maxillary, and of the 

 nature of a mucous gland. These are the superior and 

 inferior admaxillary glands. 



