254 



GENERAL BIOLOGY 



improvement in capacity for sustained, speedy and well 



directed flight, as 

 the reduction of re- 

 dundant, and the 

 readjustment of the 



remaini ng 



veins 

 proceeds. It is a 

 sign of a generalized 



^^'^^::^^.,r,.^sjMM^/Mi^. condition when 

 ^ many parts of an 



organism are found 

 performing similar 

 functions. The 



earthworm is very 

 generalized in the almost unending repetition of like parts 

 in successive segments. The malacostracan Mysis (fig. 156a) 



Fig. 157. Beard tongue (Pentstemon pubescens). 

 a, a flower viewed from the side; b, the same 

 with the side of the corolla cut a.way, showing 

 the elongated, declined and hairy fifth stamen; 

 arrow indicates the path of the entering bee. 



Fig. 158. Mysis stenolepsis (after Paulmier). 

 b, A mud cra.b. (Panopsus depressus). 



