520 PROCEEDINGS OF SECTION D. 



It may not be without interest to record, also, the average number 

 of young rats per litter. Thirty pregnant rats had in their uteri 198 

 foetuses, giving an average of 6-6 per litter. The smallest number 

 found was three (twice), and the largest 10 (once) and nine (three times). 



RAT FLEAS. 



A number of fleas on rats have been collected at various times. It 

 has been found that these are numerous, even when plague is absent. 

 It has also been noticed that they may remain on the body long after 

 rigor mortis has set in, and even until putrefaction is commencing. It 

 has been generally supposed that they leave the body as soon as it is 

 cold. 



Of 60 fleas found 32 were Pulex cheopis (Kothschild), 27 were 

 TypMopsylla musculi, and one was P. fasciatus. 



