134 



BRANCH ARTHROPODA 



Hearing. The " ears " consist of a pair of small tympanic 

 membranes, situated on the basal segment of the abdomen in 

 the locust and on the tibiae of the forelegs (Fig. 95, p. 123) 

 of the cricket and katy-did. Associated 

 with each tympanum is a vesicle filled 

 with liquid and an auditory ganglion, which 

 is connected by a nerve with one of the 

 thoracic ganglia. 



Feeding. All Orthoptera have biting 

 mouth parts, and bite off and chew their 

 food. Most of them are vegetable feeders, 

 but the mantis is carnivorous. The locusts 

 or grasshoppers have at times wrought 

 great havoc with man's crops, as both 

 sacred and secular history tell us. 



Leaping. In the leaping Orthoptera the 

 posterior pair of legs is especially adapted 

 for this purpose. They are large and long, 

 and when walking the knee-joints are much 

 higher than the insect, thus giving leverage for their prodigious 

 leaps, in which they rival the fleas in their athletic records. 



The metamorphosis is incomplete, the young (nymphs) 

 (Fig. 103) differing from the parents in size and absence of wings 

 (Fig. 104). 



Fig. 102. Wing 

 of cricket musician 

 (enlarged) , showing 

 the file at a and the 

 scraper at 6. 



Fig. 103. Calopt'enus spre'tus: a, a, Newly hatched larvae; b, full-grown 

 larva; c, pupa, natural size. (After Riley.) 



The cockroaches (Blat'tidae) are nocturnal insects, found about the 

 pantries and water-pipes of our dwellings, though in the North, according 

 to Comstock, our native species lives in woods and fields. One may often 

 find them hiding under bark, sticks, and stones. The jaws are strong and 

 toothed, and they are greedy little creatures, devouring anything they can 

 get. " eating book-bindings and bed-bugs with equal alacrity." The body 

 is flat and slippery and the legs are adapted for rapid running, enabling 



