LOCUST 427 



brain or supraesophageal ganglia by nerve fibers which pass on 

 each side of the esophagus. Nerves pass from the brain to the eyes, 

 antennae, and palpi of the head. The subesophageal ganglia supply 

 the mouth parts with nerves. The legs and wings are coordinated 

 in their movements by the thoracic ganglia. In the vertebrates the 

 nervous system is dorsal to the digestive tract, and the foreshadow- 

 ing of this evolutionary change is initiated in the insects by the 

 development in the cephalic region. 



The grasshopper is dioecious; the abdominal structures separat- 

 ing the two sexes are distinctive. The external genital structures 

 have been discussed above. The male organs consist of testes located 

 dorsal to the intestines. The sperms are borne in ducts w^hich 

 communicate with the penis, which consists of ehitinous styles used 

 in copulation with the female. In the female there are two ovaries, 

 which when mature fill the major portion of the abdomen. The 

 oviducts convey the eggs to the vagina, a duct made by the union 

 of the two oviducts, which discharges the eggs through the opening 

 at the base of the egg guide to the outside of the body. The eggs 

 are fertilized by the sperms from the spermatheca, which is dorsal 

 to the vagina and which is connected by means of a sperm duct. 

 The female is able to dig a hole in the ground with the ovipositor 

 and deposit the eggs to the depth of an inch or more. The eggs 

 are covered with a frothy substance which protects them from 

 moisture and, to some extent, from the frost. The eggs are laid in 

 the fall and hatch in the spring of the year. The development of the 

 grasshopper is by gradual metamoi'phosis. 



References 



Comstock, J. H.: Introduction to Entomology, Ithaca, N. Y., 1933, Comstock 

 Publishing Company. 



Essig, E. O.: The Insects of Western North America, New York, 1926, The 

 Macmillan Company. 



Fernald, H. G.: Applied Entomology, New York, 1926, McGraw-Hill Book 

 Company. 



Folsom, J. W., and Wardle, E. A. : Entomology With Reference to Its Ecological 

 Aspects, Philadelphia^ 1934, P. Blakiston 's Son and Company. 



Lutz, F. E.: A Fieldbook of Insects, New York, 1921, G. P. Putnam's Sons. 



Snodgrass, R. E. : The Principles of Insect Morphology, New York, 1935, McGraw- 

 Hill Book Company. 



