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TEXTBOOK OF ZOOLOGY 



ing in beetles. The compound eye consists of many facets, which 

 are the hexagonal-shaped corneal ends of structures called om- 

 matidia. The facets are convex, and insects are short-sighted. 



It has been shown by experimentation that many insects are able 

 to detect colors. Some students of the insects maintain that the 



I 

 I 



A. 



B. 



Fig. 171. — Western lubber grasshopper, Brachypephus magnus. A, male, and B, 

 female. The form found on the plains. (Photographed by Leo T. Murray.) 



compound eyes function mainl}^ in detecting movements, while 

 ocelli are used to detect light intensities. 



There is but one pair of antennae or feelers, and they vary in 

 size, shape, and position on the head among the various groups of 



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