GLANDS OF THE ORAL CAVITY. 465 



relations are unknown. Nerves proceed from the plexus caroticus ex- 

 ternus, with the vessels, into the interior of the glands; in addition, the 

 ganglion linguale (lingualis and chorda tympani] supplies the two smaller 

 pair of glands, and the facial nerve, probably with the anterior auricular, 

 the parotid. I may remark, with regard to the distribution of these 

 numerous nerves, that here also it is impossible to find any in the smallest 

 lobules of the glands, while on the other hand they are readily discovered 

 upon the larger vessels and the excretory ducts. In animals I found 

 particularly rich nervous networks upon Rivinis ducts, the tubules 

 having a diameter of 0-001-0-002 of a line. 



The secretion of the salivary glands normally contains no formed ele- 

 ments, but may accidentally present cylindrical cells from the excretory 

 ducts, or scattered, half-disorganized cells from the glandular vesicles. 

 Its physical and chemical properties, in the different salivary glands, 

 appear to differ in some respects. The parotid saliva is clear and fluid, 

 and, like the glandular vesicles themselves, contains no mucus. Ber- 

 nard and Jacubowitsch found the secretion of the sub-maxillary gland in 

 the dog to be viscid, and capable of being drawn out into threads ; ac- 

 cording to Bernard also, a watery extract of the gland itself contains 

 mucus. 



In man, the ductus Whartonianus, if laid open, is usually found to 

 contain a small quantity of a kind of mucous fluid, which, however, con- 

 sists chiefly of cylinder epithelium and broken-up epithelial cells of the 

 glandular vesicles themselves, containing only a very small amount of a 

 substance which coagulates in acetic acid, and is, perhaps, mucus. The 

 glandular vesicles, on the other hand, if crushed, usually yield a con- 

 siderable quantity of mucus, which coagulates into threads by the action 

 of acetic acid. The vesicles of the proper sublingual gland contain 

 still more mucus, and the ductus Bartholinianus also commonly presents 

 distinct evidence of it. With respect to Rivini's ducts, they are filled, 

 in man and animals, with the same yellowish, viscid, amorphous fluid, 

 coagulating into threads by the action of acetic acid, which is met with 

 in the ducts of the small mucous glands, while the glandular vesicles 

 themselves also contain abundant mucus. From all that has been said, 

 it would seem ihatRivims glands, as I will call them, must be excluded 

 from the class of salivary glands, and, as regards the three larger glands, 

 their secretion does not appear to be identical, but sometimes to contain 

 mucus (submaxillary and particularly the sublingual), sometimes to want 

 it (parotid). 



We may take this opportunity of making some observations with 

 respect to the salivary, or mucous corpuscles, of authors ; rounded cells 

 of 0-005 of a line, with one or many nuclei, which are always to be met 



30 



