1914-] F. H. vStewart : Indian Helminthology, No. II. 199 



(PI. xxviii, fig. 13) is of oval form, 0*3 mm. in length and contains a 

 single ovum encased in an eggshell of golden colour. From the 

 uterus the anterior uterine duct leads into the female atrium, on the 

 ventral aspect, as has been explained above, of the atrial circlet of 

 hooks. The two vaginae (text-fig. 3 and PI. xxix, figs. 16 and 17 

 vag.) lead out of the oviduct, and pass outward and slightly back- 

 ward to the vulvae. Each vulva is an open cup situated close to 

 one of the lateral margins, on the ventral surface, and 2 mm. from 

 the anterior extremity. The mouth of the cup is only slightly con- 

 tracted and has a diameter which measures 0*045 mm. The greatest 

 breadth of the interior of the cup measures o"o68 mm. The wall 

 of the vulva is devoid of cell-outlines and of nuclei and thus 

 resembles the ectoderm with which it is continuous. It is traver- 

 sed by fine branching fissures which contain a darkly staining 

 material. The vulva opens into the vagina through fissures of 

 this nature. The darkly staining material is neither sperm nor 

 yolk. The vulval capsule is surrounded by pear-shaped cells which 

 possess finely granular protoplasm and large nuclei, but do not 

 contain any obvious secretion. 



The main longitudinal ducts of the yolk glands open into the 

 vaginae close to the vulvae (PI. xxix, fig. 17, text-fig 3. y.g.d.). 

 The glands extend from the level of the posterior border of the 

 second pharynx as far backward as the anterior margin of the 

 Gotylophore. They are found immediately beneath the basement 

 membrane on the dorsal and lateral aspects of the body, and on 

 those portions of the ventral aspect which are not occupied by 

 the reproductive organs. The cells of the yolk glands contain (i) 

 granules which stain pink with carmine^ and (2) golden 3^ellow 

 globules. The latter are more numerous than the former. The 

 colour of the globules is identical with that of the eggshell. The 

 granules may be of yolk, but the present writer has not been able 

 to compare them with the contents of the uterine egg, owing to 

 the imperviousness of the eggshell to stains and paraffin. As 

 these glands are morphologically the same as the glands described 

 as yolk glands in other species of Polystomum, the name is retained, 

 although they appear also to function as shell glands. 



Another group of glandular cells is found at the same trans- 

 verse level as the ovary, but on the opposite side of the midline. 

 They appear to be connected with the corresponding vagina, but 

 their function is obscure. The protoplasm of these cells is filled 

 with irregular granules. 



The vitello-mtestinal canal (text-fig. 2. PI. xxix, fig. 15 v.i.c) 

 leads from the oviduct to the left intestinal branch. The present 

 writer did not find spermatozoa in any part of the female ducts. 

 Yolk cells bearing granules and globules were found in the 

 oviduct and in the left ramus of the gut near to the opening of 

 the vitello-instestinal canal. 



The Excretory System. A main longitudinal duct is present on 

 either side of the body, situated O'lS/ mm. from the lateral margin. 

 It measures 0*238 mm. in diameter and possesses a fibrous wall. 



