210 ELEMENTS OF HISTOLOGY. [Chap. xxvu. 



277. The intermediary part of the duct and its 

 passage into the alveoli is the same as in the 

 salivary glands. The cells lining the alveoli are 

 columnar or pyramidal, and show an outer homo- 

 geneous, or faintly and longitudinally striated zone 

 (Langerhans, Heidenhain), and an inner more tran- 

 sparent granular-looking zone. The nucleus of the 

 cell is spherical, and lies in about the middle. According 

 'to the state of secretion the two zones vary in amount, 

 one at the expense of the other. 



The lumen of the alveoli is very minute, and 

 in the beginning of the alveoli, i.e., next to the 

 intermediary part of the duct, are seen spindle-shaped 

 cells occupying the lumen, the centroacinous cells of 

 Langerhans. 



In the rabbit's pancreas Kiihne and Lea have 

 shown that there are peculiar accumulations of cells 

 between the alveoli, which are supplied with veritable 

 glomeruli of capillary blood-vessels. 



CHAPTER XXVII. 



THE LIVER. 



278. THE outer surface of the liver is covered with 

 a delicate serous membrane, the peritoneum, which, 

 like that of other abdominal organs, has on its free 

 surface a layer of endothelium. It consists chiefly of 

 fibrous connective tissue. 



At the hilum or porta hepatis this connective 

 tissue is continued into the interior, and becomes one 

 with the connective tissue of the Glisson's capsule, or 

 the interlobular connective tissue (connective tissue 

 of the portal canals). This tissue is fibrous, and 



