96 DIPTERA. 



the thighs thick and strong, forming admirable leaping 

 organs. The larva of the flea is a long footless grub 

 with a horny head. Fleas lay their eggs in cracks in 

 the boards of rooms, in dust, or other undisturbed 

 places ; but those species, which are parasitic on dogs, 

 cats, squirrels, and moles, lay the eggs amongst the 

 hair, and the larvae feed on minute particles of animal 

 matter. In about a fortnight the larvae are full grown, 

 they then shut themselves up in silken cocoons and 

 change to pupte, in which condition they remain for 

 about another fortnight, when the perfect insects ap- 

 pear. Animals have their own peculiar species of 

 flea-parasites, but the species belonging to one will 

 sometimes attack another. The dog-flea {Pulex canis), 

 for instance, is smaller than the human-flea, and is a 

 distinct species, yet it will attack men ; the same may 

 be said of the F. gallince, so common in hens' nests. 

 The flea that infests the squirrel is one of the largest 

 with which I am acquainted, but that of the badger is 

 larger still. The Jigger or Chigoe {Pulex j^enetrans) of 

 the West Indies and North America inserts itself be- 

 neath the skin or under the nails of the foot. Here the 

 female develops her eggs in the ovaries until she^ 

 becomes as large as a pea; if the pest is not ex- 

 tracted, it produces ulcerations, giving much paiu and 

 trouble. 



The great security against annoyance from fleas is 

 cleanliness ; various plants have been supposed to be 

 eflicacious in driving away fleas, such as Erigeron, Conyza^ 

 Pulicaria, etc., to which the term "flea-bane" has beea 

 applied. Old Tusser recommends cleanliness and worm- 



