-ENTOMOLOGICAL NEWS. 355 
ie have been removed from shipboard since the present 
*rancisco epidemic. ° 
enocephalus canis Curtis on rats appears to be more nu- 
us in the metropolis than on rats collected in the trans 
tion. This species was perhaps contributed to the rat 
ts feline and canine hunters. This accounts probably for 
er number of Ctenocephalus canis found on rats in the 
¢ densely populated quarters. On shipboard Ctenocephal- 
— is eeee comected from rodent hosts. The ship cat 
t _Feputec to be a rat hunter. The constant petting and 
i by the sailors does not stimulate hunting natural prey 
he inaccessibility of holds of vessels is a substantial check 
at catching. Thus an interchange of parasites between 
) animals was not to be expected nor in any instance has 
my as known to occur. Numerous ship pets inadvertently left 
in| the cabins during fumigation proved victims to the sulfur 
mes. One species of flea only, the cat flea, was found on 
few fleas of the human species Pulex irritans Linn. 
- d from live or dead rats, It was the least numerous 
tthe ane found on animal hosts. Those collected were 
arbored by brown rats in a grain warehouse and: stable in 
%- wr the study of ship rat fleas twenty-five vessels were in- 
_ gpected and methods of rat extermination investigated. The 
essels in every instance were thoroughly sealed and fumigated 
th three per cent. SO2 gas obtained from burning crude sul- 
_ The rats when exposed to five hours of sulfuring are 
i after the third hour, when they scamper about to escape 
P dondly fumes before they succumb. Invariably the dead 
8 oe are found with opaque lenses,—an evidence of blindness 
+ asp death. Formerly three hours was the length of expos- 
"ure to sulfur fumigation. The rats were rarely killed, but mere- 
ly rendered stupid by the fumes and men with clubs killed 
_ them. Upon collecting these rats I found that the fleas soon 
revived and gave evidence of their activity when the contain- 
ers were opened. It was concluded that three hours’ exposure 
