THE DOG AND CAT-FLEA. 133 
by stating that a single flea has been known to draw, with 
ease, a silver cannon weighing 70 times its own weight. 
Good and thorough ventilation of the rooms, cleanliness, 
and the free and repeated use of insect-powder will drive 
fleas from houses infested by them. 
The flea infesting man differs greatly from those intfest- 
ing animals; it has no spines on the head or on the back of 
the thorax, while the posterior margins of the segments of 
the thorax and abdomen possess rows of stiff hairs pointing 
backwards. The peculiar comb-like bristles upon the head 
and the posterior part of the thorax found upon the dog-flea 
and others are absent. 
THE DOG AND CAT-FLEA. 
(Pulew serraticeps Gerv.). 
This is the well-known flea infesting cats and dogs. 
Wherever pets are kept that harbor the above parasites these 
latter are certain to cause much trouble, as they seem to pre- 

Fig. 111.—Dog and cat-flea. Greatly enlarged. Original. 
fer carpets and similar places, in which they conceal them- 
selves during the day. In this way they will reach the bodies 
of persons walking over them, and tender-skinned children 
and ladies are frequently poisoned by their bites. Fleas are 
not like mosquitoes or other blood-sucking insects, which 
bite but once if not disturbed; they bite as they move about, 
literally ‘‘bite on the run.”’ 
