24 



AK Ili A IIZÜKA. 



The testes (fig. 4, t.) are present in two pairs, in segments X 

 and XI. 



The sperm-sacs (fig. 4, sp.s.) likewise in two pairs, are racemose 

 and lie in segments XI and XII. The spermatozoa are in various 

 stages of development. Almost fully developed spermatozoa have also 

 been observed in the body cavity. 



The funnels (fig. 4, f.) of the spermducts are, as usual, provided 

 with long cilia and lie in two pairs in segments X and XI. The vas 

 deferens (fig. 5, v.d.) runs posteriorly, on each side as far as segment 

 XVIII, where it enters the mass of the spermiducal gland, (fig. 5, sp. 

 gl. g.) in the neighborhood of the junction of the glandular and muscular 

 portion ! of the latter, eventually to open into the lumen of the. gland 

 (figs. 5 .V G, sp. gl. c.) 



There is only one pair of spennici ucal glands. They belong to the 

 tabular type (figs. 4 & 5) and occupy segments XYII-XIX, being 

 much convoluted. Each gland consists, as already mentioned, of a 

 glandular and a muscular portion, the latter leading to the exterior. At 

 first, on dissecting the worm, it appeared to me as if the vas deferens 

 opened at the junction of the two portions of the gland ; hut a close 

 examination of serial sections has shown that this is not the case. The 

 vas deferens is continued without interruption after joining the gland, 

 and runs in the midst of the glandular cells towards the posterior blind 

 end of the gland, tracing in general, the convolutions of the latter. It is 

 at this end that the vas deferens really opens into the lumen of the 

 gland. In other words the spermiducal gland is not a blind diverticulum 

 but a direct continuation of the course, of the vas deferens. The 

 glandular portion passes at the anterior end into the strongly muscular 

 portion. The latter gradually tapers towards, and finally opens extern- 

 ally at, the male pore inside the pad-like ridge on segment XVIII. 



The wall of the vas deferens is composed of a single layer of dis- 

 tinctly nucleated cells, and its inner surface is provided with long cilia 

 (fig. 6, c. and w.v.d.) The glandular portion of the spermiducal gland 

 consists of two distinct layers, the inner columnar epithelial layer, and 



