43 



Dissect another specimen, opening it on the ventral side. 



Make a diagram representing the relations of the various 

 parts of the reproductive organs of the male locust. 



If fresh specimens can be obtained, kill one, remove a 

 seminal vesicle from it, tease apart the vesicle on a glass 

 slip, mount it in glycerine, examine it with a high objective, 

 and observe the bundles of spermatozoa. Each bundle con- 

 sists of a great number of hair-like spermatozoa. 



The reproductive organs of the female. — Take an adult 

 female locust, remove the wings and hind legs, and make a 

 slit in the dorsal wall of the body extending the whole length 

 of the thorax and abdomen. Spread'open the specimen, pin 

 it to a piece of cork, and place it under water for dissection. 



The ovaries lie above and on each side of the stomach : 

 the cephalic end of them is supported by the ligament of the 

 viscera. The egg-tubes of which the ovaries are composed 

 occupy the same relative position as the testicular follicles of 

 the male, but fill a larger proportion of the body-cavity. 



Push laterad the egg-tubes of each side so as to expose 

 the alimentary canal ; cut in two the alimentary canal in the 

 thorax, and remove the caudal portion of it ; this will expose 

 two large bundles of muscles connected with the dorsal pair 

 of valves of the ovipositor. Carefully split these apart and 

 fasten them aside with pins. When this is done, the last 

 ganglion of the nervous system will be exposed. Carefully 

 remove this ganglion, cutting such nerves and tracheae as 

 may be necessary. 



Each ovary consists of many egg-tubes which are arranged 

 in two rows, and open into an oviduct ; the two oviducts unite 

 near the caudal end of the body and form the common ovi- 

 duct or vagina. 



That portion of each oviduct into which the egg-tubes 

 empty is greatly enlarged ; this is termed the egg-calyx^ and 

 serves as a receptacle for the ripe eggs. 



