ROACHES AND OTHER ANCIENT INSECTS 



The roaches, the dragonflies, and the mayflies attest 

 the great antiquity of insects, for since these forms ex- 

 isted practically as they are today in Paleozoic times, the 

 primitive ancestors of all the insects, of which we have 

 no remains in the geological records, must have lived in 

 times vastly more remote. However, though we may 

 search in vain the paleontological records for evidence 

 of the origin and early development of insects, the sub- 

 sequent evolution of the higher forms of modern insects 

 is clearly shown by the species preserved in eras later 



Fig. 60. A mayfly, representative of another order of primitive 

 winged insects having numerous relations in Paleozoic times. 

 (Twice natural size) 



than the Carboniferous. Such insects as the beetles, 

 the moths, the butterflies, the wasps, the bees, and the 

 flies are entirely absent in the older rocks, but make their 

 appearance at later periods or in comparatively recent 

 times, thus confirming the idea derived from a study of 

 their structure that they have been evolved from an- 

 cestors more closely resembling the paleodictyopteran 

 types of the Carboniferous beds. 



The long line ot descent of the roach, with almost no 

 change of form or structure, furnishes material for a 

 special lesson in evolution. If evolution has been a 



[97] 



