156 GENERAL ZOOLOGY 



rivers. The blind crayfish has small and abortive eyes, but 

 its sense of touch is developed to a marvelous degree of 

 delicacy. Dr. Hay says that although the crayfishes may 

 be resting quietly on the bottom of a rivulet, it is impossible 

 to capture them with a net. They feel the jar in the water 

 and dart backward with great accuracy to a protecting rock. 

 In general appearance the blind crayfish differs from others 

 chiefly in having an exoskeleton which is so clear that one 

 may see the animal's stomach as a blue mass within, and 

 in being provided with antennae longer than the body. 



Crayfishes are eaten by fish large enough to swallow 

 them, and they in turn catch small fish with great facility, 

 and also insect larvae, snails, tadpoles, and even frogs. 

 They have been known to prey upon each other, and also 

 to eat both dead and living plant and animal food. They 

 seem to be omnivorous. 



In America crayfishes seem to be used as food chiefly by 

 the French portion of our population. Possibly the rapid 

 depletion of the lobster fisheries may cause people generally 

 to turn to the lobster's nearest edible relative. In France 

 the crayfish industry is quite extensive, there being many 

 farms on which crayfishes are raised for the market. 



