SALIVARY GLANDS. 



257 



often so faintly outlined that the whole structure has the appearance 

 of a large polynuclear giant cell. 



The demilunar cells have been variously interpreted by different 

 observers. They have been regarded as permanent cells with a 

 special secretion, as transitional structures, and again as cells des- 

 tined to replace the degenerated mucous cells. Stohr (87) be- 

 lieves that the cells of the acini are never destroyed in the process 



Crescents of 

 Gianuzzi. 



200. From section of human submaxillary gland. 



of mucous secretion, and that the crescents of Gianuzzi are there- 

 fore merely a complex of cells containing no secretion, which have 

 been crowded to the wall by the adjacent enlarged and distended 

 cells. Solger (96), on the other hand, does not regard the demi- 

 lunes as transitional structures whose function is to replace the 

 destroyed cells, but considers them to be permanent secreting cells 

 an opinion which he bases on the results of special methods of 



Connective - 

 tissue. 



Gland cell 



of acinus. 



Intralobu- 

 lar duct. 



Intermedi- 

 ate duct. 



Fig. 201. Section from parotid gland of man. 



investigation. 



According to him, then, the mucous salivary glands 

 are mixed glands, in that the demilunes consist of cells of a serous 

 type, while the remaining elements are mucous in character. The 

 destruction of mucous cells during secretion is not admitted by him 

 (compare also R. Krause). This latter view seems more in accord 

 with recent observations. 

 17 



