428 NATURAL HISTORY OF HARTING. 



cleanliness. From these eggs are hatched, long, 

 worm-like, very active, though footless grubs, the food 

 of which does not appear to have yet been satisfac- 

 torily ascertained. Those which are hatched early in 

 the season are full-fed in about twelve days, they then 

 spin themselves up in small cocoons of silk and 

 become pupae, in this stage they remain about a 

 fortnight longer, when they emerge in the perfect 

 state. The later bred larvae do not undergo their 

 transformations till the following spring, but in either 

 case the fully-developed flea is a marvel of muscular 

 strength and activity. Many proofs of this are on 

 record, and, to say nothing of the astonishing feats of 

 flees broken to harness, or trained to military ex- 

 ercises and other public performances requiring enor- 

 mous muscular power, it has been ascertained by 

 Entomologists, that the common bed flea can clear a 

 distance two hundred times the length of its own 

 body at a bound. 



More than twenty distinct species of flea have been 

 discovered and described, the Dog flea (Pulex Cants) 

 is specifically different from the Bed flea (Pulex 

 irritans) ; Ceratopsyllus Talpcz, the largest of the 

 family, may be found on the Mole ; Pulex Felis on 

 the cat ; Pulex Sciorurum on the squirrel ; Pulex 

 Erinacei on the hedgehog; and Pulex Vespertilionis 

 is appropriated to the bat. For specimens of all 

 these species, therefore, no distinct locality need be 

 explored by any of our Halting readers, who might 

 feel disposed to add to their intellectual recreations 

 the practical study of this order of insects. 



