SECT. 135.] SALIVARY GLANDS. 287 



in length; the remaining part of the Avail consists of connective 

 tissue, with numerous, very dense networks of fine and thicker 

 clastic fihrcs, to which, in the submaxillary duct, a thin layer of 

 smooth muscular fibres is superadded. The vessels present the 

 same conditions as in the mucous glands. 



Nerves pass from the plexus caroticus externus, with the vessels, 

 into the interior of the glands, where they are met with in small 

 numbers upon the vessels, excretory ducts, and other parts, and 

 appear to end with free extremities. Besides, the submaxillary 

 ganglion (lingualis and chorda tympani) supplies the two smaller 

 pairs of glands ; and the facial nerve, and, pi'obably, the auricularis 

 anterior supply the parotid. 



The secretion of the salivary glands is, normally, destitute of de- 

 finitely formed constituents, but may accidentally contain cylindrical 

 cells of the excretory ducts, or half- decomposed cells from the 

 acini. Its physical and chemical properties are different in the dif- 

 ferent salivary glands. The saliva of the parotis is clear and fluid, 

 and, like the acini themselves, contains no mucus. The secretion 

 of the submaxillaris, on the other hand, contains mucus and is 

 ropy; and, according to Bernard, a watery extract of the gland 

 likewise yields mucus. The sublingualis contains still more mucus. 

 Hence the salivary glands, with the exception of the parotis, are 

 very closely related to the mucous glands of the oral cavity, and, 

 at any rate, there is nothing to warrant a decided separation of 

 the glands in question. 



This is the proper place to make a few remarks on the salivary or mucous 

 eorpuscles of authors. These are roundish cells, o - oo5'" in size, with one or 

 several nuclei, which, so to speak, are constantly found in the fluids of the 

 mouth, although in very various quantities, and which are looked upon by 

 most authors as coming from the mucous or salivary glands, but incorrectly ; 

 since the examination of both kinds of glands, and of their excretory ducts, 

 shows that they do not secrete any definitely formed constituents. The mu- 

 cous corpuscles are, in my opinion, merely products of the mucous membrane 

 of the oral cavity ; and, indeed, although almost constant, still not altogether 

 normal, but a kind of exsudation of pus-corpuscles, with which, also, they are 

 acknowledged to have the greatest resemblance in their structure. Their 

 origin is still unknown, yet it is most probable that they come, in some way 

 or another, from the epithelium. 



For the investigation of the mucous membrane of the oral cavity, perpen- 

 dicular sections of fresh or dried pieces, or such as have been hardened in 

 absolute alcohol, are especially necessary. In these the papilla} and epi- 

 thelium are very distinct, and become still more clear on the addition of very 

 diluted caustic soda, when the deepest epithelial cells also readily come into 

 view. The papilla) are to be studied in macerated pieces, or when it concerns 

 only their position and form, in perpendicular or horizontal sections, treated 



