592 



INSECTS AT llOMi 



Spence), is exceedingly complicated, but is formed of modifica- 

 tions of parts of the mouth which already existed, and not ol" 

 entirely new organs. Indeed, like the beak of the suctorial 

 Heteroptera, the beak is formed of the lips and jaws, which are 

 modified so as to suit the wants of the insect. These organ.<, 

 though similar in character, vary much in form in the different 



'iff^^m'^'^: 



1 . Pulex taTpje, 2. Pnlex irritans. 3. Culex pipiens, male. n. Pulex talpse, mentum 



and palpi. b. Do., side view of head. c. Do., palpus. d. Do., tarsus. f. Pulex iiritans. 

 pupa. /. Do., meutum and palpi. g. Culex pipiens, male, palpus. h. Do., antenna. 



species, as may be seen by reference to Woodcut LXIX. Figs, a 

 and /, of which the former represents the mouth of the male 

 Flea, and the latter that of the common Flea. 



The transformations of this insect are worthy of some notice. 

 The female Flea lays a very few eggs, seldom more than twelve 

 in number, and deposits them in any convenient spot. Hearth- 

 rugs are favourite resting-places for these eggs, and so are the 

 little crevices in the floor or walls in which the adult insects 



