On the Affinities of the Pulicites. cxlv 



wings, which have been created out of the scales observed and figured 

 by Hooke, on the sides of the thoracic segments. Now, supposing 

 that wings were to be detected on an insect previously regarded as 

 apterous, the comparative anatomist is at once furnished with a clew 

 to its position in one of those systems which all entomologists have 

 admitted as the basis of their methods : but alas ! this favourite hypo- 

 thesis must fall before the searching investigation of the comparative 

 anatomist ; these scales are neither wings nor the representatives of 

 wings. This assertion I base upon the following facts : — first, no 

 wings have the character of these scales : secondly, no wings have 

 the position of these scales : thirdly, true wings, in a closely allied 

 genus, exist in company with these scales. These preliminary re- 

 marks appeared necessary, in order to bring the book-history of the 

 Ilea up to the period of the commencement of my inquiry ; and I wish 

 it to be distinctly understood that I disclaim all idea of originality in 

 my conclusion that the flea is a dipterous insect; my object being 

 rather to prove that those profound entomologists are correct who 

 have supposed this to be the case. 



§ 1. Economy and Metamorphosis of the Flea. 



It seems scarcely necessary to state that the flea is a lively little 

 insect of a red-brown colour, remarkable for its power of leaping, and 

 for its disagreeable propensity to suck our blood; but a few facts con- 

 nected with its history are not so universally known, and are worth 

 recapitulating. The bite of the flea is much more annoying to some 

 persons than to others ; in fact, it may be assumed from the everyday 

 use of the term, "a mere flea-bite," that the majority of mankind re- 

 gard its attacks with great contempt. It is not thus with all : were I 

 to indulge in a little bit of autobiography, my own pulicine experi- 

 ences would excite some surprise : I will, however, only describe the 

 feeling and appearance produced. The feeling is that of intense and 

 intolerable itching, accompanied with burning heat and a greatly 

 accelerated pulse ; the surface is swollen around the puncture in a 

 distinct and well-defined circular space, as large as a shilling, and 

 becomes white, the skin exterior to this circle is red, and the punc- 

 ture itself intensely red ; these effects last for twenty-five minutes. 

 The female flea is commonly, perhaps always, the aggressor. I have 

 acquired some considerable skill in capturing fleas while in the act of 

 sucking my blood, and they have invariably proved females. There 

 are several species, almost equally common, but not yet distinguished 

 by specific characters ; Pulex irritans I regard as an absolute myth. 



