628 



ZOOLOGY 



paired tube with muscular walls opening on the exterior imme- 

 diately below the anus. Around the genital aperture are a series 

 of chitinous processes, the gonapophyses, which subserve copula- 

 tion. 



In the female there are two groups of ovarian tubes or ovariolcs, 

 each group or ovary (Fig 501, ov.) consisting of eight. The 

 ovarioles of each group are united together anteriorly, where they 

 are connected by a ligament to the dorsal body-wall. Posteriorly 

 each group is connected with a lateral oviduct (cd.). Each ovarian 

 tube has a beaded appearance, owing to its containing a row of 

 ova, which increase in size posteriorly. The two oviducts unite to 

 open by a median aperture on the sternal surface of the eighth seg- 

 ment of the abdomen, A pair of unsymmetrical sacs opening 

 together in the middle of the sternum of the ninth segment 



Fio. 500.— Cockroach. Male 



reproductive organs, lateral 

 view. duct. ej. ductus ejacula- 

 torius with mushroom-shaped 

 gland ; stem. 7, sternum of 

 seventh segment of abdomen ; 

 terg. 7, tergum of the same 

 segment ; test, testis. (After 

 Miall and Denny.) 



ccH.c/id- 



Fig. 501.— Cockroach. Female re- 

 productive organs, coll. (fid. colleterial 

 glands ; od. oviducts ; ov. ovaries. 

 (After Miall and Denny.) 



constitute the spermatheca or receptaculum seminis. A pair of 

 ramifying glandular tubules, the colleterial glandsj^coll. gld.), open 

 behind the spermatheca. A series of chitinous gonapophyses, which 

 aid in carrying the eggs, are situated between the female genital 

 aperture and the anus. 



Development. — The eggs are enclosed about sixteen together 

 in chitinous capsules, the substance of which is secreted by the 

 colleterial glands. They are laterally compressed, concave on one 

 side (the future ventral side), convex on the other (the future 

 dorsal side). 



The mature egg in the lower part of the ovary is enclosed in a 

 follicle composed of a single layer of cells, within which is the thin 

 chitinoid egg-shell or chorion perforated by a number of micropylar 

 apertures. After the processes of maturation and fertilisation, the 

 segmentation-nucleus undergoes division, the result being the 

 formation of a number of irregular amoeboid cells, which are 



