190 Records of the Indian Museum. | Vol. XIV, 



to V. Graff,* Stoppenbrink^ and others. Outside the muscular layers 

 there exists a cellular coating which probably represents the insunken 

 parts of the lining epithelium. Processes from the cells are occasionally 

 seen to extend to and to join the ciliated lining layer. 



As already indicated, the oviduct receives the vitelline glands at 

 several points of its course. The mode of the connection is quite similar 

 to that described by Kennel,^ Ijima,* v. Grafi and others in PI. gono- 

 cephala, PI. polychroa, Dendr. lacteum and some land-planarians. It is 

 effected by means of a pyriform or spherical giant cell, which usually 

 contains an internal space filled with spermatozoa and probably com- 

 municating with the lumen of the oviduct. The cytoplasm of the cell 

 is finely granular and exhibits but little affinity for haematoxylin ; the 

 nucleus is by far larger than those of surrounding tissues. In no case 

 have I been able to demonstrate the polycellular club-shaped body 

 which was described by Stoppenbrink in place of the single giant cell. 

 In sections the cellular cords of the yolk-gland are seen to be attached to 

 the surface of the giant cell, but exactly how the yolk-cells reach the 

 oviduct lumen cannot be elucidated. As has been pointed out by 

 previous authors, the giant cell in question is probably of a glandular 

 nature. It may be that its secretion disperses into the parenchyma and 

 acts as an attractive agent, which may cause the yolk-cells to collect at 

 its position. Eventually the cell breaks up and disappears, and then the 

 yolk-cells may be said to be in a position to make their way unhindered 

 into the oviduct. 



The receptaculum seminis (uterus) is a large sac-like organ occupying 

 a position between the pharyngeal chamber and the penis. Its wall 

 is an epithelium made up of large columnar cells of a glandular nature, 

 resting on a delicate basement membrane, beneath which are layers 

 of fine circular and longitudinal muscular fibres. In the specimens 

 I have examined, the organ seems to have been in secretory activity, 

 the cells containing some refringent globules besides being vacuolated. 

 In one individual, the organ contained spermatozoa enveloped in a 

 coagulum of the secretion, while in another it contained a well-formed 

 spermatophore of an elongate ovoidal shape. 



From the postero-superior end of the receptaculum arises the vaginal 

 canal, which runs backward, passing dorsally to the left of the penis, and 

 then dips below to open into the vestibulum. The vagina is internally 

 lined with an epithelium made up of cylindrical cells resting on a fine 

 basement membrane. Just external to this are found the internal 

 longitudinal, the middle circular and the external longitudinal muscular 

 layers in direct succession. Of these the circular layer is best developed, 

 thickest in the middle parts of the course of the canal. Towards both 

 ends of the canal, the muscular layers as a whole gradually grow thinner. 



^ V. GrafiF, L., 1899. Monographie der Turbellarien. II. Tricladida terricola. 

 2 Stoppenbrink, F., 1905. " Der Einfluss herabgesetzter Ernahrung auf den histo- 

 logisohen Bau der Siisswassertricladen. " Zeitschr. f. wiss. Zool, Bd. LXXIX. 



* Kennel, J., 1879. " Die in Deutschland gefundenen Landplanarien, Rhrjnclwde- 

 mus terrestris O. F. Mull, und Geodesmus bilineatus Metschn." Arbeiten des zool.-zoot. 

 Inst, zu Wilrzburg. 



* Ijima, I., 1884. " Untersuchungcn iiber Bau und die Entwicklung«gescliichte 

 der Siisswasser-Dcndrocolen (Tricladcn)." Zdtschr. f. wis6. Zool, Bd. XL. 



