28 Art 2.— T. Kaburaki : 



ring either singly or two together at a time in the receptacle are of 

 a shape and size well agreeing with the one described from the 

 seminal vesicle, so far as my observations go. The pyriform shape 

 of the spermatophore of PI. vivida apparently stands in the relation 

 with the shape of the space of its origin, the seminal vesicle, and 

 the adjoining parts of the common vas deferens. In this con- 

 nexion I may mention that in both PI. burmaensis and PI. an- 

 nandalei Kab. the spermatophores I have found in the receptacle 

 were also of a shape corresponding to that of the part of the penis- 

 lumen known as the seminal vesicle, as already noted. In the 

 former species the shape was elongate-ovoid, and in the latter 

 tubular. 



The eosinophil nature of the substance of the spermatophore 

 capsule decidedly differentiates it from the cyanophil secretion of 

 the glandular cells discharging into the seminal receptacle. As 

 already described, Micoletzky based his observation on the stain- 

 ing property of the receptacle fluid enclosing a spermatophore, 

 using haematoxylin-eosin for the stain, and assumed that the 

 receptacle secretion changes from cyanophil into eosinophil during 

 the process of the capsule formation in that organ. I have obtained 

 a similar result with PI. vivida under the same circumstances of 

 condition and treatment ; however, I am inclined to interpret 

 the differential staining as due to the receptacle fluid being in the 

 process of dissolving up the substance of the spermatophore 

 capsule. 



The paired ovary is situated ventrally between the first and 

 second branches of the anterior gut trunk. It is of an ovoid 

 shape, the major axis being parallel to that of the worm-body. 

 The ovary is, as usual, made up of ova in several stages of develop- 

 ment, surrounded by the tunica propria. No trace of the 

 pigmented tissue could be observed around the ovary. 



The vitelline glands are represented by cellular cords with 

 cells arranged in two or more rows. They are very extensively 

 distributed from the ovarian region nearly to the end of the body, 

 filling up the interspaces between the gut diverticulae. They 

 connect with the oviduct at numerous points. The cells of the 



