REPRODUCTION". 171 



into a spiral of about one turn. From the tube a csecal process 

 is given off, which may correspond with the accessory gland 

 attached to the duct of the spermatheca in many Insects (e.g., 

 Coleoptera, Hymenoptera, and some Lepidoptera). The sperma- 

 theca is filled during copulation, and is always found to contain 



A 



B 



Fig. 96. Diagram to show the theoretical (upper figure) arid actual position of the 

 hinder abdominal sterna in the female Cockroach. V, uterus ; s, spermatheca. 

 The nerve-cord is introduced into both figures. 



spermatozoa in the fertile female.* The spermatozoa are no 

 doubt passed into the genital pouch from time to time, and 

 there fertilise the eggs descending from the ovarian tubes. 



T 1 <^ O 



The external reproductive organs of the female Cockroach 

 belong to the 7th, 8th, and 9th somites. The 7th sternum is 

 incompletely divided into anterior and posterior sections, and 

 the posterior section is split into lateral halves. These are 

 joined by a flexible membrane, which admits of the wide 

 separation of the halves, when copulation or the passage of the 

 large egg-capsule renders it necessary. The vertical faces of 

 the membrane, which are pressed together when the parts are 

 at rest, are stiffened by chitinous thickenings. 



If the succeeding sterna retained their proper place, as they 

 do in some Orthoptera (e.g., the Mole Cricket), the 8th and 9th 

 sterna would project beyond the 7th, while the rectum would 



It is a striking proof of the sagacity of Malpighi, that he should have observed 

 in the Silkworm the spermatophore of the male ( " in spiram circurnvolutum per- 

 siruile semen") and the spermatheca of the female. His reasoning as to the 

 function of the spermatheca wanted nothing but microscopic evidence of the actual 

 transference of spermatozoa to establish it in all points. Audouin and Siebold 

 supplied what was wanting nearly two centuries later, but they mistook the spirally 

 wound spermatophore for a broken-off penis, and Stein ("NVeibl. Geschlechtsorgane 

 der Kilfer, p. 85) first arrived at the complete proof of Malpighi's explanation. 



