20 



G. O. SARS. 



[No. L 



on the male sexual organs of the Cyprididae believes that the 

 spermatozoa, poured off from the testicular appendages and thus 

 received in the interior of the body itself, are contained on either 

 side within a distinct very elongate duct („upper part of the 

 vas deferens"), forming numerous convoluts and finally debouching 

 in the upper extremity of the ejaculatory apparatus to be des- 

 cribed below. On carefully dissecting several specimens, 1 have 

 failed to detect any trace of such a duct and cannot but doubt 

 its real existence. In my opinion the fully developed sperma- 

 tozoa are simply received within the cavity of the body, as is 

 also the case with the ova, and remain here until copulation is 

 effected. The true efferent apparatus consists on either side of 

 two very sharply defined parts, a very peculiar cylindrical body 

 extending along the side of the posterior part of the body oblique- 

 ly from above backwards (fig. 6 x), and a narrow duct (v) 

 originating from the inferior extremity of this body and repre- 

 senting the true vas deferens. This duct immediately makes a 

 sharp curve forwards and penetrates the neck-shaped part joining 

 the copulative organs to the body, its mode of termination having 

 not yet been exactly ascertained. As to the remarkakle tube- 

 shaped part representing the upper division of the efferent appa- 

 ratus, it exhibits a very peculiar and highly complicated struc- 

 ture. At first sight (fig/ 6 x) it has the appearance of being 

 composed of two tubes, the one lying within the other and form- 

 ing a more compact axis, from which at regular intervals lateral 

 projections are given of crossing the lumen of the outer, more 

 pellucid tube or sheath. On closer inspection with a strong 

 magnifier (fig. 9) the inner tube is found to be supported by a 

 complicate chitinous skeleton, divided into short regular segments, 

 about 34 in number, each bearing a whorl of radiating spines 

 reaching the outer cuticle of the enveloping sheath. The latter 

 would seem to be for the most part built up by numerous radiat- 

 ing muscles acting upon the inner cylindre. At each extremity 



