( exvu ) 
Fleas in this condition, unable to satisfy the cravings of 
an empty stomach, are most persistent in their efforts to 
obtain food, and lose much of their accustomed shyness. In 
two instances fleas in this blocked condition were fed on a 
shaved area on eight rats in succession, and in one instance 
on twelve. Two minutes was the time allowed on each rat, 
and in some instances so eager were the fleas that they would 
make a second attempt before they could be removed. In 
one experiment three out of nine rats on which two blocked 
specimens of X. cheopis had been fed in succession died of 
pest, and in a similar experiment with C. fasciatus the two 
fleas were responsible for the death of three rats out of nine. 
This stoppage of the alimentary canal does not apparently 
necessitate the death of the flea if the block is only in the 
proventriculus. We have among our sections some which 
show the process of the clearance of an old block and the 
formation of a new one in its several stages. It seems ques- 
tionable, however, if the flea can survive long enough without 
food for the plug to disintegrate if it forms a solid cone in the 
distended oesophagus, such as is exhibited in some of the 
specimens I have to show. 
Blocked fleas have been observed by us to emit a minute 
droplet of blood from the base of the pricker while feeding, 
and from its tip at the moment of removal from the skin, 
and our sections show that blood remaining in the oesophagus 
and pharynx is heavily infected. 
Dr. JorRDAN, commenting on this very important paper, 
observed that it proved conclusively that infection was 
through the mouth of the flea, and not, as he had previously 
thought, through the faeces. 
A curtous Larvat Hasir.—Dr. K. Jorpan exhibited some 
specimens of a lepidopterous larva which is most remarkable 
for its adaptation in habits and colour. The specimens were 
discovered by the Rey. A. Miles Moss, F.E.8., who is chaplain 
of the English Church at Parad and a most ardent observer 
of Lepidoptera, having bred and painted, both at Para and 
in Peru, many hitherto unknown larvae of butterflies and 
moths, particularly Papilionidae, Sphingidae and Saturnidae. 
When collecting near Pard a Saturnid caterpillar with black 
