The Grasshopper 



345 



eliminating, by natural selection, the less handsome. It has been sug- 

 gested by some also that the female, who carries the eggs, by being less 

 gaudy in appearance is also less conspicuous and, therefore, not so likely 

 to be caught by natural enemies. 



In all female insects there are a pair of ovaries (Fig. 222) usually 

 formed of many small tubes called ovarioles. From the ovaries the 

 oviducts pass out into a terminal region, the vagina, which is sometimes 

 also paired. This latter organ is usually formed by an invagination from 

 the outer part of the body to meet the oviducts. Near the place of 

 meeting of vagina and oviducts or branching off from that region there 

 is a receptaculum for receiving and holding the male sperm received 

 during copulation. 



Then there are accessory glands which secrete a sticky substance, or 

 cement, as the eggs pass through the oviduct. These glands are known 

 as colleterial or sebific ( ) glands which open in turn 



into the dorsal portion of a capacious pouch, the bursa copulatrix, 



through a duct. This bursa rests 

 on, and opens directly into, the 

 oviduct of the female. Grasshoppers 

 have an external hard posterior re- 

 gion of the body known as an ovi- 

 positor (Fig. 225). 



The males possess a pair of 

 testes usually formed of many small 

 tubes. These tubes, in turn, connect 

 with two ducts, the vasa deferentia, 

 which carry the sperm to the termi- 

 nal portion called an ejaculatory 

 duct. The ejaculatory duct may 

 have one or two openings which may 

 be formed by the union of both vasa 

 deferentia or by an invagination 

 meeting these ducts. 

 The seminal vesicles, usually paired, open from either the vasa 

 deferentia or the ejaculatory duct. Here sperm are stored. Often there 

 are accessory glands whose secretion unites the sperm into packets 

 known as spermatophores. There may or»may not be an external copu- 

 latory organ though in the grasshopper there are a pair of these, called 

 cerci. Often there are also external hard parts as in the female though, 

 of course, these are not ovipositors. 



The sperm are placed in the seminal receptaculum of the female by 

 the male and may remain there for many years. The queen bee only 

 copulates once, and that on her first and only flight, and yet the sperm 

 have remained alive so that eggs which were laid thirteen years after- 

 ward were fertile. 



Fig. 225. 



Rocky Mountain locust: a, a, a, Female in 

 different positions, ovipositing; b, egg-pod ex- 

 tracted from ground, with the end broken 

 open; c, a few eggs lying loose on the ground; 

 d, e, show the earth partially removed to il- 

 lustrate an egg-mass already in place and one 

 being placed; /, shows where such a mass has 

 been covered up. (After Riley.) 



