10 John Rennie, 



than any other? Should they not be found more or less evenly 

 distributed throughout the whole gland? It is abundantly proved that 

 they are not. In certain types, at least, they are habitually found to 

 be unequally distributed in respect that they are aggregated mostly at 

 the splenic end. A group which appears to illustrate this peculiarity 

 well is the Ophidia (See Oppel, Lehrbuch Vergleich. Anatomie p. 805), 

 and it is not without interest in this connection to recall the presence 

 of the relatively large and constantly occurring juxta-splenic "principal 

 islet" of many Teleostean fishes. It has occurred to us to look more 

 particularly for the effects of fasting, not in the part of the pancreas 

 where islets are known to occur more or less numerously at all times, 

 but in a region where if any marked change has taken place as a 

 consequence of inanition such changes will be indisputable. In this 

 connection we record here a case which tests the matter in this 

 particular way. 



The Case of a Grass Snake (Tropidonotus natrix). 



A gi-ass snake, which in the month of April last year (1907) was 

 placed in a glass jar amongst some dry moss, was through an over- 

 sight forgotten. It was discovered in the month of October, having 

 been five and a half months without nourishment, and that at a time 

 when it is accustomed to feed. It had been purchased from a dealer 

 and the date of its last meal was not known. Indeed it is questionable 

 if the animal had broken its fast of the previous winter. When dis- 

 covered in October it was very feeble, inert, and was evidently at the 

 point of death. It was immediately killed with chloroform, the pancreas 

 was removed along with the spleen to which it closely adheres, cut 

 in two and fixed in corrosive-acetic mixture. After some hours it was 

 washed, dehydrated, embedded and the entire pancreas cut in serial 

 sections of from 10 to 15 microns in thickness. In the anterior half, 

 with the exception of two very small patches which on the first survey 

 were overlooked, the whole series consisted of typical pancreatic acini. 

 In the posterior half of the pancreas no islets were encountered until 

 near the end, where they were found to be numerous, of various sizes, 

 and sometimes very irregular in form. There are parts which tak6n 



