34 SPECIAL HISTOLOGY. 



always entirely closed, and the epithelium extends them, so that 

 one is led to the belief that the secretion is developed inde- 

 pendently, out of a substance excreted into the cavity of the 

 organ. That this is possible and actually takes place, indeed, 

 elsewhere (e. g. suppuration upon mucous membranes which 

 are still covered by their epithelium), is not to be denied ; 

 and the sole difficulty about such a hypothesis is, that in 

 this case the import of the tonsillar and lingual follicular 

 glands (for which, also, all that has been said, holds good), 

 becomes highly problematical. If they do not occasionally 

 burst, their function, as regards secretion, can only be to elabo- 

 borate in their interior a fluid, which, when it subsequently 

 enters the cavity of the gland, is especially fitted to form its 

 proper secretion. For the rest, the similarity of the follicles in 

 question, especially with those of the solitaryand Peyerian glands, 

 and also with those of the spleen 1 and lymphatic glands, would 

 indicate another series of possibilities, into which, however, I will 

 not enter, because in all the organs in question the anatomical 

 facts and the physiological relations have hitherto been by no 

 means completely determined.] 



3.— SALIVARY GLANDS. 



i, 136. 



The salivary glands, i. e. the parotid, the submaxillary, the 

 sublingual, and Rivini's glands, agree so closely in their struc- 

 ture with the racemose mucous glands, that it would be quite 

 superfluous to enter into any detailed description of them. 

 They are compound racemose glands, and they might be re- 

 garded as aggregations of numerous mucous glandules. In fact, 

 the primary and secondary lobulations which are observed in 

 these glands correspond, the latter to the entire mucous gland, 

 the former to its lobes. The secondary lobulations then be- 

 come united into still larger groups, and a certain number of 

 these constitute the whole gland. The excretory ducts corre- 

 spond with the number of the lobulations of the gland ; they 

 are more or less branched, and in their final relations resemble 

 those of the mucous glands. 



1 [For some additional facts in favour of these resemblances, see notes § Spleen. 



—Eds.] 



