INSECTS ATTACKING CATTLii. 



Recently the part played by the rat flea in the dissemination of 

 plague has been discussed by Captain W. G. Listen. This article 1 

 should be read in full, but his conclusions briefly are that the rats, infested 

 with fleas, get plague, infect the fleas and die ; then the fleas, with the 

 infection of plague in them, have no food and attack any available 

 animal ; should that animal be man, he gets plague from the bite of the 

 flea. The flea in this case is simply the transmitter of the plague, and 

 only attacks man when its proper food (the rats) have died of plague or 

 migrated. If experience bears out this theory, the importance of the 

 flea is immensely increased and the commencement of plague epidemics 

 can perhaps be checked. 



Ticks. 



The commonest external parasites of cattle are ticks, creatures which 

 when full grown have four pairs of legs and are allied to the mites, 



FIG. 316. 



The Persian Tide. (Magnified.} 



spiders and other arachnids. They may be seen fastened to the skin 

 of cattle and grow to a large size. Specimens have been sent in from 

 almost every domestic animal in India, and, in one case, the Persian Tick 2 

 was found upon human beings. 



1 Journal of the Bombay Natural History Society, XVI, 2, p. 253, April 1905. 



2 Argas persicus. F. 



