308 SALIVARY GLANDS AND PANCREAS 



like depressions which receive the bases of the secreting cells. The 

 function and origin of these " basket cells " is not at present known. 

 They are readily recognized by their deeply stained and flattened 

 nuclei which are contained within the thin cytoplasmic cell body. 

 The appearance of the secreting epithelium varies with its 

 activity. During rest the granular secretion accumulates within 

 the cell, until the non-granular zone is reduced to a narrow rim 

 at its basal extremity and the nucleus is obscured and pushed 

 somewhat basalward. The cell therefore becomes much swollen 

 and the alveolar lumen almost obliterated. During activity the 

 zymogen granules are discharged into the lumen, the cell shrinks 

 and becomes clearer, the nucleus appears more distinct, and the 

 granular zone becomes progressively narrower, the basal non- 

 granular zone being correspondingly increased in breadth. In 

 this basal zone elongated granules have been demonstrated, which 

 are possibly to be regarded as prozymogen (" basal filaments " of 

 Solger*). 



The serous cells are provided with systems of secretory canal- 

 iculi which, beginning at the glandular lumen, invest the cell with 

 a network of canals which lie in the intercellular substance and 

 may even send short offshoots into the body of the cell itself. 

 These canaliculi are considered to be characteristic of the serous 

 acini and are not found in relation with the cells of thp mucous 

 acini (Fig. 252). 



The mucous acini may contain only mucus secreting epithelium, 

 or they may also include certain finely granular cells which 

 resemble the epithelium of the serous glands. The former variety 

 of acinus is found in the mucous glands at the base of the tongue 

 and in the soft palate ; the latter in the sublingual gland, in the 

 glands of N"uhn, and in the mucous glands of the lips and cheeks. 



The serous appearing cells of the latter form of mucous acinus 

 are frequently arranged as crescentic groups bordering upon the 

 adjacent mucous cells. Such groups are known as the demilunes of 

 Haidenhain or crescents of Gianuzzi. They occur at the periphery 

 of the acinus, their base being applied to the membrana propria, 

 their inner margin sometimes reaching the glandular lumen, but 

 more frequently separated therefrom by the overlapping of the ad- 

 jacent mucus cells. The demilunes are frequently found at the 

 , blind extremity of the secreting acinus, but they may also occur 

 along its sides. 



* Festschr. f. C. Gegenbaur, 1896. 



