332 ORESSWELL SHEARER. 



the gland secretion. It is connected with tlie penis by a 

 strand of cytoplasm that runs to its ventral side, and is con- 

 tinuous across the median line with a strand from a similar 

 cell from the opposite side. Posterior and ventral to this 

 ai-e a number of small, darkly staining cells. They are 

 lenticular in shape, with prominent nuclei. They fill up the 

 corners between the large cells. The largest cell of the 

 gland is placed about the middle or slightly towards its 

 posterior end. The section shown in fig. 24 passes just 

 behind its posterior border. The nuclei of the smaller cells 

 are rod-shaped, and frequently bent in a semi-circular form. 

 On the inner wall of the gland, close to Avhere it abuts against 

 the penis-sheath, are a number of darkly staining masses of 

 nuclear material. The ends of all the gland-cells converge 

 on the penis. When the cells are charged with secretion 

 their nuclei are seen to be large and round, with a well- 

 marked karyotheca. The karyoplasm is collected into a 

 darkly staining kai-yosome. In the cells that have dis- 

 charged their secretion, on the other baud, the nuclei are 

 invariably long and rod-shaped, with a uniformly staining 

 karyoplasm, and no karyosorae. 



In fig. 23 are represented some of the cells of the posterior 

 group under high magnification. The cytoplasm forms a 

 superficial layer which throws threads aci'oss the vacuolar 

 interior of the cell. The nucleus is always situated about the 

 middle of the cell and is of considerable size, and contains a 

 darkly staining karyosome. 



The compai-tment of the generative region holding the 

 glands is sharply separated from the anterior part of the 

 segment, which contains the testis, as already explained. 

 This is clearly separated from the granule cells and the 

 vesiculee, which are within the limits of the testis proper, 

 and enclosed by its membrane. 



The region of the accessory gland is often seen distended 

 with the accumulation of secretion within the gland. With 

 dark ground illumination this appears opaque and whitish in 

 colour. In the surface view of a living preparation the two 



