CLASS INSECTA: ORDER COLEOPTERA. 



215 



Pulicidae. The Fleas are wingless Dipters. 

 dergo a complete metamorpho- ~ s 



sis, and the imago possesses 

 rudimentary wings. Their 

 tough skin makes it difficult to 

 crush them between the fingers, 

 while their wonderful muscular 

 power enables them to jump 

 two hundred times their length, 

 and to draw a hundred times 

 their weight.f 



They un- 



Pulex irntans, Human Flea. 



ORDER COLEOPTERA. 



General Characteristics. The Coleopters (sheath- 

 winged) have the an- 

 terior wings (elytra) 

 of a horny texture, 

 and the posterior, 

 membranous. The 

 latter are the sole 

 organs of flight. The 

 mandibles are very 

 strong, and often 

 armed with acute 

 teeth on the inner 

 margin. Their met- 



Lachnozternafusca, May-beetle. amorphosis is COm- 



August, before the winged adult period. Most of those which are born in August 

 live for a month or six weeks, and die at the coming of frost. A few probably winter 

 over and survive until mid-summer, and thus maintain the existence of this useful 

 species, to which civilized man owes more than he can readily estimate, and with 

 which he can dispense only when the health of our cities and towns is looked after 

 with far greater vigilance and intelligence than is perhaps likely to be the case for 

 several centuries to come." 



* Horse-ticks, sheep-ticks, bird-ticks, bat-ticks, bee-lice, etc., are other anomalous 

 forms of Diptera. 



t Pleas have been trained to show their strength and docility. The so-called 

 " learned fleas," exhibited in Paris, went through military evolutions, standing on 

 their hind legs and shouldering tiny spears : and two of them drew a companion in 

 a little wagon, a fourth sitting on the coachman's box and wielding the whip. The 

 Spectators viewed this wonderful exhibition through magnifying glasses. 



