62 



Annals Entomological Society of America [Vol. Ill, 



LENGTH OF LIFE IN VARIOUS MEDIA. 



C. actitits. 



*M— Male; fF— Female. 



The controls 5 M. 5 I", were all dead on or before the seventh 



da^^ 



In the medium ()( moistened sawdust mixed with a few wheat 

 jrrains it was found that the wheat sprouted in the sawdust and 

 held sufficient moisture to provide a suitable condition for larvae 

 as well as for adults. The mould which formed in a short time 

 did not seem to affect the insect life. 



It is seen that the fleas did not fare well in the medium of 

 dry sand. The sand was mixed with cla\' dust which would rise 

 whenever the fleas hopped in the vial. As a consequence death 

 resulted presumably by stoppage of the spiracles. 



It will be seen from a survey of this table that fleas taken from 

 the natural host may be kept alive without food for a considerable 

 time. The medium of moistened sawdust with a few grains of 

 wheat seemed to answer the moisture requirements for flea life. 



LOCOMOTION. 



The only literature that has come to our notice on the jumjv 

 ing powers of fleas appears in the Journal of Hygiene, 1906, \^ol. 

 6. p. 464. Here we have a note: "It had previously been found 

 that a rat flea could not hop farther than five inches." The 

 s])ecies in question in these experiments was the L. chcopis, which 

 is found to the extent of 99% on the rats in India. 



