INSALIVATION. 167 



glands. In addition to these structures, the mucous mem- 

 brane of the tongue is provided with a number of simple and 

 compound follicular glands, which extend over its entire 

 surface, but are most abundant at the posterior portion, be- 

 hind the circumvallate^papillse. 



In the pharynx and the posterior portico, of the buccal 

 cavity, are found the pharyngeal glands and the tonsils. 

 In the pharynx, particularly the upper portion, racemose 

 glands, like those found in the mouth, exist in large num- 

 bers. The mucous membrane is provided, also, with numer- 

 ous simple and compound mucous follicles. The tonsils, situ- 

 ated on either side of the fauces between the pillars of the 

 soft palate, consist of an aggregation of compound follicular 

 glands, held together by fibrous tissue. The number of 

 glands entering into the composition of each tonsil is from 

 ten to twenty. 1 



The secretion from the glands and follicles above enu- 

 merated cannot be obtained, in the human subject, unmixed 

 with the fluids from the true salivary glands. It has been 

 obtained, however, in small quantity, from the inferior ani- 

 mals, after ligation of all the salivary ducts. This secretion 

 is simply a grayish, viscid mucus, containing a number of 

 leucocytes and desquamated epithelial scales. It is this 

 which gives the turbid and opaline character to the mixed 

 saliva, as the secretions of the various salivary glands are 

 all perfectly transparent. The fluid from these glands in 

 the mouth is mixed with the salivary secretions ; and that 

 from the posterior part of the tongue, the tonsils, and the 

 pharyngeal glands passes down to the stomach with the ali- 

 mentary bolus. This secretion consequently forms a constant 

 and essential part of the mixed saliva." 



Mixed Saliva. Although the study of the distinct secre- 

 tions discharged into the mouth possesses considerable physi- 



1 KOLLIKER, Manual of Human Microscopic Anatomy, London, 1860, p. 284. 



