REPRODUCTION AND HEREDITY 



145 



In every case we find the form and action of an 

 insect's ovipositor suited to the position in which eggs have 

 to be placed. The long ovipositor (Fig. 36, A) of a female 

 phasgonurid grasshopper enable her to bury her eggs deep 

 in the ground, and the long tapering telescopic abdomen of 

 a female crane-fly or 

 carrot-fly enables her 

 to achieve the same 

 result on a smaller 

 scale. The serrated 

 processes of a sawfly's 

 or a cicad's oviposi- 

 tor serve to cut in- 

 cisions in plant tissues , 

 while the dart-like 

 egg-laying organ of » 

 an ichneumon fly 

 pierces the body- wall 

 of a caterpillar, and 

 prepares for the life 

 of her larva as an 

 internal parasite. Be- 

 sides laying the eggs 

 the female often fixes 

 or protects them by 

 a hardened fluid Fig 

 secretion of glands 

 opening into the 

 vagina. To such pro- 

 tective action further 

 reference will be made 



a later chapter 



m 



36. — A, Hinder Abdominal Segments 

 (7-10) and Ovipositor of Longhorned 

 Grasshopper (Conocephalus), lateral view. 

 X 3. B, Diagram of Hinder Abdominal 

 Segments (6-10) and developing Ovipositor 

 of a typical female insect, c, cerci ; v, 

 vulva ; ga, processes (gonapophyses) of 

 eighth segment ; gb, inner and gc, outer 

 processes of ninth segment. After R. E. 

 Snodgrass (Anatomy of the Honey Bee, 



(p. 302). ■'°"- 



The sperm-cells are developed, as already mentioned, in 

 the testes of the male, whose abdomen contains on either 

 side in the dorsal region a testis which corresponds to the 

 female's ovary, and is composed, like that organ, of a number 

 of tubes which open into a duct called, in the male, the 



L 



