322 



R. R. BENSLEY 



TABLE 3 



Showing variation in number of islets per milligram in neighboring pieces of the 

 splenic portion of the pancreas of two guinea' pigs 



No. 1 



Total weight of splenic portion including the above weights 0.479 



Total number of islets in the splenic portion 16,606.0 



Average number of islets per milligram 35.5 



No. 2 



Total weight of splenic portion — 0.494 



Total number islets in splenic portion 10,744 . 



Average number of islets per milligram 21 . 7 



amount by the method usually employed of selecting a sample 

 of the pancreas from the splenic end and comparing the number 

 of islets in a certain area of section is untrustworthy, unless a 

 very large number of sections be examined, and even then the 

 results may lead to incorrect conclusions owing to the unequal 

 distribution of the islets in the pancreas and to the difficulty of 

 recognizing the smaller islets. Thus, in employing the method 

 of comparison of sections, the investigator makes certain assump- 

 tions which reference to the tables will show not to be supported 



