REPRODUCTIVE ORGANS OF KUKENTHALIA ROREALIS. 



193 



distally confluent, a,nd they communicate with the peribranchial 

 cavity by a short, narrow aperture which is well observable near 

 the vas deferens (c/. text-fig. 8). 



These facts are of a special interest ; then, owing to the above- 

 mentioned arrangement, the passage of the egg is secured : the 

 oviduct opening Avidely iiito the brood-pouch, the egg, having left 

 the oviduct, must be laid into the brood-pouch, where it probably 

 remains until it is fully developed. 



The oviduct is of considerable width, especially the distal 

 part, which is rather sac-like, and the wall is deeply folded on 

 one side. 



Text-figui*e 6 represents a transverse section of the genital 

 pouch on a level with the bifurcation of the vas deferens. The 

 latter is on the point of forking, on account of which it appears 

 somewhat broad. The figure shows how the oviduct is somewhat 

 compressed from side to side ; it is lined with a low epithelium. 



Test-fia'ure 5. 



Kilkenthalia borealis (Gottscli.). 



Tlie reproductive organs from the oatsidc. X 23. 



hp. Brood-pouch, o. Ovarium, od. Oviduct, t. Testis, vd. Vas deferens. 



Moi'e distally, on certain parts of the wall, a strongly ciliated 

 epithelium was observed. As appears from the figure, the ciliated 

 epithelium of the vas deferens is also well developed. 



The brood-pouch has the form of a large double-walled sac 

 with a constricted neck. It generally contained one embryo. 

 In some individuals it is of considerable length and width, pro- 

 jecting beyond the genital pouch. Text-figure 5 represents it at 

 a stage somewhat less developed. 



In individuals containing no embryos a brood-jDouch has also 

 been observed, though highly reduced with regard to form and 

 size. Such an interesting stage is shown by text-figure 7, where 

 the brood-pouch is represented by a short blind sac or an appendix 

 in connection with the oviduct ; and in zooids with rudimentary 

 reproductive organs, as for instance in that represented by 

 text-figure 3, the presence of such a blind sac can also be 

 stated, as will be seen from text-fissure 8. The last-mentioned 



