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EVOLUTION OF ANIMALS 



Part V 



Fig. 30.3. Carpenter ants (Camponotus), about half an inch long, and burnished 

 black, in the corridors which they have cut. These ants are common in and out of 

 houses. Their young are here shrouded in white cocoons. (Photograph by Lynwood 

 Chace. Courtesy, National Audubon Society.) 



and mid-August. At the end of that time, the progeny of the original female 

 would weigh 800 million tons providing every one were living. 



Insects are like old miniatures in their perfection within small size. Some 

 are larger than the smallest vertebrate and others are smaller than the largest 

 protozoan. The smallest North American beetles can scarcely be seen with- 

 out a lens, yet their structure is as complex as any other insect. The Central 

 American rhinoceros beetle {Megasoma elephas), a relative of our common 

 June beetle, is five and a half inches long. 



The large size of ancient animals was no more successful for insects than 

 for the great reptiles. Only the fossils are left to tell the old story, too much 

 body to feed and no place to hide. A fossil dragonfly (Meganeura) has a wing 

 expanse of two feet; there are no such living ones (Fig. 30.5). 



Habitats and Distribution. Although their remote ancestors came from the 



