82 



eludes that the total island tissue of the human pancreas is appreciably 

 less than that of the gl. parathyreoidea. Heiberg's calculation of 

 the amount of island tissue in one human pancreas which was not rich 

 in islands gives the proportion of island tissue to acinous tissue as 

 1 ; 31 or about 2.6 grammes of island tissue in the pancreas examined. 

 So far as is indicated most of the above estimates were made upon 

 pancreases from individuals of near middle life, 25 to 50 years. 



In contrast with these findings Heiberg gives another reckon- 

 ing of the proportion of island to acinous tissue in a pancreas from 

 a subject 102 years old. In this subject he finds that the relative 

 proportion of island to acinous tissue is considerably higher, the 

 proportions (case No. 48 — 1910) of island tissue to acinous tissue 

 being in the splenic portion (2 estimates) 303 to 1000 and 9 to 100 

 and in the duodenal portion 14 to 100. These proportions are con- 

 siderably higher than the highest given by any other observer. 



Opie, Heiberg, Sauerbeck and Laguesse have studied the 

 relative distribution of the islands of Langerhans in the head, body 

 and tail of the pancreas. With few exceptions they find the islands 

 most numerous in the tail of the gland. Heiberg further states that 

 while it is true that the splenic end usually contains the greatest 

 proportion of islands, their number does not increase as the spleen 

 is approached. The same author was also unable to observe any 

 difference in the relative distribution of the islands in so far as the 

 periphery and depth of the gland is concerned. 



By taking the results of these four investigators we are enabled 

 to obtain a rough estimate of the number of islands of Langerhans 

 in the human pancreas as will be indicated below. 



Method. 



This note consists of scarcely more than an attempt to extend 

 to man Bensley's intra vitam method for the study of the fresh 

 pancreas. Accordingly, frequent reference will be made to his work. 



The method employed by me for estimating the number of islands 

 of Langerhans in the human pancreas consists in the post- vitam in- 

 jection of a very dilute solution of either neutral red or a commer- 

 cial janus green (obtained from L. A. Metz & Co., New York). It 

 is essentially the same as that employed by Bensley for the cat, dog, 

 etc. Such human material as the above is so scarce that my attempts 

 to determine the best dilution for the human subject were limited. 



