9. THE REPRODUCTIVE SYSTEM 



101 



mpa 



Fig. 68. Transverse section of a female Polybrachia annulata in the metameric region of the 

 metasoma. 



eg - gland cell of epidermis ; cil - cilia ; со - dorsal ciliated band ; сое HI - metacoele ; cpa - coelom 

 of adhesive papilla ; cv - corpus cardiacum ; cut - cuticle ; dgt - duct of pyriform gland ; ep - epi- 

 dermis ; epo - epithelial wall of ovary ; gt - pyriform gland ; mes - mesentery ; ml - longitudinal 

 muscle layer; mpa - muscle layer of papilla; my - myocyte; nc - neurocord (giant nerve fibre); 

 nl - thickened marginal region of dorsal nerve plate ; ov - ovary ; p - cuticular plaque ; pa - papilla ; 

 per - peritoneum; pgt - pore of pyriform gland; pn - dorsal nerve plate; sf- lamellar secretion of 

 pyriform gland; vd - dorsal blood vessel; vov - ovarian vessels; vv - ventral vessel. (After Ivanov, 

 1958a.) 



perhaps best be called the ovifunnel or ovarian funnel; the external narrower 

 limb forms the oviduct proper. The funnels fuse with the two sides of the 

 mesentery, which thus comes to form their common median wall, with the 

 dorsal vessel pushing between them from above. The anterior lip of each 

 funnel fuses with the body wall and the hind end is continuous with the 

 oviduct, which runs forward from the hind end of the funnel (after making a 

 U-bend) between the body wall and the funnel itself. Then it penetrates into 

 the longitudinal muscle layer of the dermis and runs for a short distance 

 embedded in this layer before it finally opens through the latero-ventral 

 genital pore. This is all shown diagrammatically in Fig. 66. 



The walls of the funnel consist of a low unciliated epithelium, which 

 becomes considerably thicker towards the hind end of the organ, especially 

 towards the point of union with the oviduct, and takes on a glandular nature. 



E 



