THE ANIMALS AND MAN 



Fig. 1. 



Locusts on 



wild oats. 



(Natural size; 



from life.) 



structure of a part and its 

 function or business are close- 

 ly related. A grasshopper's 

 hind legs are specially long 

 and strong so as to enable the 

 grasshopper to hop; or we 

 may put it differently and 

 say that the grasshopper can 

 hop because its hind legs are 

 specially long and strong. In 

 whichever way we look at this 

 relation between the power of 

 an animal to do something in 

 a special way and its posses- 

 sion of parts specially fitted 

 for doing this something, 

 whether it be hopping, or 

 flying, or singing, or breathing 

 under water, it must be kept always plainly 

 in mind that such a close^ relation does 

 exist. Therefore when we study the 

 make-up of an animal, examining care- 

 fully the various parts of the body, we 

 should always remember that this partic- 

 ular make-up or structure is closely con- 

 nected with the things the animal can do, 

 and the special manner in which it does 

 them. 



The grasshopper. — Grasshoppers, better 

 called locusts, of some kind can be readily 

 t^j^ found along roadsides or in fields (fig. i). 

 Collect several specimens, keeping some 

 alive and dropping the others into the 

 killing-bottle (see p. 472). Examine care- 

 fully a dead specimen. Note that the body 



