THE SPLENO-PANCREATIC INTERNAL SECRETION. 395 



number was determined in a sectional area of 0.5 square cen- 

 timeter. Sections about 10 millimeters thick were made from 

 the enlarged duodenal portion of the pancreas, or the head; 

 from the midportion, or body; and from the splenic end, or 

 tail. The following table gives their number in an area of 

 0.5 square centimeter in sections taken from the head, body, 

 and tail of ten normal organs: 



BODY. TAIL. 



13.0 30.0 



25.0 42.0 



4.0 19.0 



10.0 13.0 



18.0 59.0 



27.0 26.0 



18.0 29.0 



10.0 29.0 



32.0 61.0 



23.0 32.0 



Average 18.3 18.0 34.0 



"The table shows that the islands are more abundant in 

 the tail, or splenic end, than in the head and in the body, 

 where they are present in approximately equal number. They 

 are almost twice as numerous in sections from the tail as in 

 those from other parts. Since the number in only one plane 

 is recorded, in order to obtain their actual relative abundance 

 it is necessary to square these figures. They are then found 

 to be slightly less than three and a half times as numerous in 

 the tail as elsewhere. 



"The cells composing the islands resemble those of the 

 acini. They have a large, round, occasionally oval, vesicular 

 nucleus and a conspicuous cell-body. The basal zone of the 

 secreting cell, as is well known, stains deeply with nuclear 

 dyes, for example, haematoxylin or methylene blue, while 

 the central portion, which contains zymogen granules, remains 

 unstained. The cells of the island, however, do not stain with 

 nuclear dyes, while with eosin their protoplasm takes a homo- 

 geneous bright-pink color. The nuclei differ but little from 



