IXSECTS. 



263 



fast days of the church. Americans who have eaten them describe them 

 as far from palatable. 



Last among the true flies come a small group which spend their adult 

 lives as external parasites on birds and 

 mammals. In some cases, as that of the 

 horse-tick figured here, this life has not 

 continued long enough to greatly affecl 

 the insect, but in other cases it has re- 

 sulted in the complete disappearance of 

 the wings. One form is remarkable for 

 being provided with wings, and living 

 on birds during a portion of its exist- 

 ence, and then migrating to the hair of 

 some mammal, and there dropping its organs of flio-ht. 



Fig. 255. —Horse-tick 

 (Hippobosca equina), 

 enlarged. 



— Bat-tick 

 ( ffycti ribia), an • \- 

 ample of a wi: 



fly- 



Some entomologists regard the fleas as extremely modified flies, while 

 others think that they have nothing to do with the two-winged forms 

 which we have just left. These, however, are abstruse questions and need 

 not be discussed here, but the weight of authority now seems to be in favor 

 of the latter view. 



The general appearance of the fleas is well shown in our cut. They 

 are wingless forms, the hind legs of which form well-developed leaping- 

 organs, while the mouth parts are modified into an 

 admirable piercing and sucking organ whose capac- 

 ities are known to all. There are several species of 

 fleas, some of which will breed upon the human body, 

 while others will torment man, but require for their 

 development the flesh and blood of some other ani- 

 mal. Most noted among the fleas is the celebrated 

 jigger-flea of tropical America. It is known under 

 a variety of names, such as chigoe, chique, pique, all 

 of which are readily seen to be modifications of one 

 fundamental word. The larva of the jigger is much like that of the more 

 familiar form. It lives in the earth and there undergoes its transforma- 

 tions. The adult female displays a marked preference for the human f 

 and when occasion offers, she quickly burrows beneath the skin ami there 

 matures her eggs. Of these there are an enormous number, and their 

 growth soon swells the abdomen out into a spherical sac. to which the 

 of the body bears about the same proportions as in the case of 

 white ant already described. This growth soon produces a severe sore, and 

 unless the parasite be removed a dangerous ulcer results. Next the i 



Fig. 257. - Flea I P 

 larg 



