134 



THYSANOURA. 



a lion to effect the same object ; and a little consideration will show that the 

 expression is not exaggerated. The hungry lion can but make a meal, and 

 then must wait for his returning appetite. The flesh-fly brings her twenty 



FIG. 139. METAMORPHOSES OF FLESH-FLY. 



thousand young ones, ready for the work. Each of these for five days is con- 

 stantly employed ; and when we consider that these voracious maggots, in 

 that space of time, increase in weight two hundredfold, and that they are 

 further capable of giving birth in a short time to other insect legions, we per- 

 ceive at once their adaptation to the important duty thus intrusted to them. 



FIG. 140. - DOMESTIC FLY {Magnified). 



The Spider Flies (Hippobosca)* are parasitic, and, strange to say, their 

 females give birth to pupae instead of eggs or larva:, hence they have been 

 designated Pupipara.^ These pupae are of considerable size, and at first very 

 soft, but their skin soon hardens into a pupa-case. These insects are re- 

 markable from having no wings. Some of them inhabit the nest of birds, and 

 live by sucking the blood of the little nestlings, whose warmth contributes to 

 their development. 



The Forest Fly (Hippobosca equina) is notorious for its incessant attacks 

 upon horses ; and in some districts appears in great numbers. Another species 

 conceals itself in the wool of sheep, from which animals it derives its food ; 

 and there are some not furnished with wings, that are exclusively resident in 

 the hair of bats. 



TUFT-TAILED INSECTS. ORDER THYSANOURA.J 



These insects are without wings, and undergo no metamor- 

 phosis. They are distinguished by the possession of peculiar 



j, hippos, a horse ; /36cr/cw, bosco, to feed on. 

 fPupa, a fupa; pario, I bring forth. I dv<ravos, thysanos, a tuff ; ovpd, oura, a tail. 



