REPRESENTATIVE INSECTS 



353 



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 (Figs. 203 and 204). 



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 lo- 

 cated dorsal to the intestines. The sperms are borne in ducts which 

 communicate with the penis, which consists of chitinous styles used 

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



Fig. 206. 



Fig. 205. — Male reproductive organs of Rhomaelia microptera. Te., testes; Y.D-, 

 vas deferens. (From White, General Biology.) 



Fig. 206. — Female reproductive organs of Rhomaelia microptera. C.S., copula- 

 tory sac; O.T. ovarian tube with eggs; Ov., oviduct; Va., vagina. (From White, 

 General Biology. The C. V. Mosby Co.) 



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 duet. 

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



