SMALLWOOD. — POLYCERELLA ZOOBOTRYON. 621 



formly granular. For a short distance (from 15 to 20 micra) from the 

 opening of the prostate duct, the cells (Figure 6, a) are narrow and 

 elongated and carry long cilia, often 3 micra in length. The nucleus 

 is much smaller than in any of the other cells, and the cytoplasm is 

 coarsely granular. 



The fundus of this flask-shaped prostate is largely occupied by the 

 glandular area, a patch of thickened epithelium about 50 micra across. 

 The cells in this glandular area are greatly enlarged, even at the edge 

 of the patch, as shown in Figure 6, c. The conditions represented in 

 Figure 6, d, show the number of layers of cells and their arrangement. 

 At the bottom of the figure are some small basal cells which, together 

 with a few larger ones, make up two rows similar in appearance to the 

 cells regularly lining the gland (Figure 6, b), except that cells are fre- 

 quently found in the second row which show the beginnings of the 

 secretion so common in the distal cells of the glandular patch. The 

 cells which cover the free surface of the glandular patch are greatly 

 enlarged, especially in that part of each cell which is distal to the nu- 

 cleus. The cytoplasm contains a number of spherical masses which, in 

 preparations fixed in Hermann's mixture, are made up in part of 1 to 3 

 blackened corpuscles, the remaining portion of the mass taking no 

 stain. The whole effect is like that of a vacuole containing differen- 

 tiated bodies. After fixation in Miiller's fluid, followed by haematoxy- 

 lin, these masses are not apparent. That these minute bodies are 

 secretions of the cell is abundantly shown by the fact that identical 

 bodies nearly fill the prostate gland, and that special drops similar in 

 form are often attached to the ends of these cells (Figure 6, d). 



There are also found in the contents of the prostate gland numer- 

 ous spermatozoa, and some bodies which it is difficult to explain from 

 the present preparations. They are of about the size of the nuclei in 

 the distal cells of Figure 6, d, but the detailed structure has degenerated 

 to such an extent that one cannot recognize any relationship between 

 them and other cells or parts of cells found in the organism. Pohl (: 05, 

 p. 434) finds abortive, undeveloped eggs in the ampulla of the sperm 

 duct, which may be the key to the explanation in this case. The bodies 

 appear much like pseudo cells in Hydra (Wager :09, Figure 14, Plate 

 3), which would mean that some undeveloped eggs had been set 

 free and were being broken down in the prostate gland. A second ex- 

 planation is equally probable: that the distal ends of the gland cells 

 break off and the nucleus gradually undergoes degeneration. In only 

 one instance, however, was there any evidence of such a breaking off 

 of the tip end of the cell (see condition of one of the cells in Fig- 

 ure 6, d) ; but I am convinced that this is not the usual method of 



