THE INSECTS 



237 



Part of the ving of a moth 

 (samia), magnified to show 

 the arrangement of scales 

 partly rubbed off. 



praying mantis, and many others. All of the above insects have 



the hind wings, when present, folded up lengthwise against the body 



when at rest, mouth parts fitted for 



biting, and an incomplete metamorpho- 

 sis. They are thus placed in an order 



called Orthoptera because the posterior 



wings are folded straight against the 



body when at rest (orthos, straight, 



pteron, wing). 



The Butterfly. The body of the 



butterfly, as that of the grasshopper, is 



composed of three regions. Compared 



with the grasshopper, the wings and 



legs show the greatest differences in 



structure. The legs of the butterfly are relatively smaller and 



weaker than those of 

 the grasshopper, while 

 the wings are rela- 

 tively larger in the 

 first-named insect. 

 Evidently the butter- 

 fly spends much of its 

 time in the air. 



If the wing is rubbed 

 with the finger, dust 

 comes off it, leaving 

 the wing transparent 

 or membrane-like. 

 Under the microscope 

 the wing is seen to be 

 covered with thou- 

 sands of little colored 

 scales, each of which 

 fits into a socket in 

 the wing. These 

 scales cause the name 



Monarch butterfly : adults, larva, and pupa on milk- j (1 ' 



weed. From photograph loaned by the American ^P^OP (UplS, 



Museum of Natural History. SCale, pteron, Wing) to 



