332 



ZOOLOGY. 



is voracious, and leads a different life from the quiescent, 

 sleeping pupa or chrysalis, which takes no food ; on the 

 other hand, the imago or butterfly has mandibles, which, 

 are rudimentary, and incapable of biting, while the maxillae,, 

 or "tongue," which were rudimentary in the caterpillar, 

 become now greatly developed ; and the butterfly takes 



' v^-^'' 



Fig. 296. — Eml,t/.) of a 

 Water-beeUe (BydrophUus). E, 

 egg ; K, head ; ol, npper lip; m, 

 month ; on, anU'nnae ; J&j. man- 

 dibles ; *,, *,, maxillae ; B, 

 thorax; S,, 6,, 6,, legs; *,-*,„, 

 ten pairs of rndimentary abdo- 

 minal legs, of which all except A, 

 disappear before the insect 

 hatches ; a, anns,— After Kowa- 

 levsky. 



Pig. 297.— Profile view of embrya 

 Honey-bee, lettering as in Fig. 

 296. .SJf, uervoasciird; oG, brain; 

 D, digestive canal ; aeh, the oeso- 

 phagns ; St, stignutai op nings of 

 the tracheal system ; J?, heart. — 

 After BlatschlL 



liquid food and but little of it, while its surroundings and 

 mode of life are entirely changed with its acquisition of 

 wings. Thus the butterfly leads three different lives, differ- 

 ing greatly in structure, externally and internally, at these 

 three periods, and with different environments. 



