98 DIFFERENT SEATS OF OEGANS OP SENSE. 



as ours do, but laterally ; several pairs of breathing- 

 holes arranged along the sides of the body ; and two 

 kinds of eyes. Moreover, unquestionable organs of 

 sense occur in very different parts of the body. The 

 Crustacean genus Mysis, as already mentioned, has ears 

 in its tail; one group of sea- worms (the Polyoph- 

 thalmata) have a pair of eyes on each segment of the 

 body. 



Of Amphicorine, a small worm of our coasts, M. de 

 Quatrefages says that often,* "C'est la queue qui marche 

 la premiere, explorant evidemment le terrain avec une 

 grande activity et donnant autant de signes d'intelli- 

 gence et de spontaneite que pourrait le faire la partie 

 anterieure du corps. . . . Cette queue porte a son 

 extremite un disque elargi gur lequel sont places deux 



points rouges. . . . Je ne 

 mets nullement en doute que 

 ces points ne soient en effet 

 des organes de vision." He 

 was not able, indeed, to make 

 out their finer structure. On 

 the other hand, the lateral 

 eyes of the Polyophthalmata 

 possess a well-formed lens. 



We need not, then, assume 

 that the organs of hearing 

 in insects must necessarily 

 be in the 

 that they 

 trated in 

 bod,y. 

 known that grasshoppers and 



-Part of ]pg of Grasshopper 

 (Gryllus); after Graber. o, t, n, b. 

 Tympanum. 



head, or, indeed, 

 need be concen- 

 part of the 



one 



It had lon£ 



been 



* Ann. des Set. Nat., 1850. 



