Tha spermatogenesis of Peripatus (Peripatopsis) balfouri. 341 



nectiag widely separated chromatin masses. Possibly this case repre- 

 sents the commencement of hypertrophy, whereby a normal nucleus 

 becomes transformed into a nucleus of a giant cell. The other case 

 (Fig. 213) was a huge nucleus, with a thin envelope of cytoplasm, 

 found in another testis among resting spermatocytes. This nucleus, 

 besides its volume, was peculiar in containing two large, spherical, 

 nearly homogeneous bodies (n.2 Fig. 213) which stained very faintly 

 while the much smaller true nucleoli stained deeply; these bodies 

 should probably be classed in the large category of problematical 

 "nucleolar" structures. No other nucleus found resembled this one 

 in its size or in the presence of the peculiar "nucleolar" bodies. 



As has been already noted, the giant spermatogonia were most 

 abundant in a testis ia which degenerating cells in the zone of the 

 spermatogonia were also most numerous. Each such degenerated cell 

 shows a more or less rounded , deeply-staining mass (probably the 

 atrophied nucleus) lying in a clear, almost structureless substance 

 enveloped by a membrane. Often the degenerating cells occur together 

 in pairs , sometimes in larger groups. The mitoses of the giant 

 spermatogonia show signs of degeneration especially in the small size 

 and faint staining-power of the achromatic spindle, as compared with 

 the normal mitoses. Most of them further are characterised by an 

 unusually large amount of yolk (Figs. 215 A, 216, 217, 221, 224, 225), 

 an amount which possibly stands in some relation to their abnormalities, 

 if it is not a direct cause of them: it would seem that this large 

 amount of yolk hindered the processes of mitosis. These are reasons 

 for considering that the giant spermatogonic mitoses result in de- 

 generation of the cells. In Fig. 220 is given a pole view of a monaster 

 stage : here there are 28 chromosomes, and in the cell a large rounded 

 body (x) staining intensely like the chromatin ; this body appears to 

 be not yolk, but nucleolar or chromatin matter in a hypertrophied 

 state, and would appear to point to hypertrophied degenerative 

 processes in the cell. The other case. Fig. 227, represents a cell of 

 the size and general clear appearance of a giant spermatogonium, 

 but contains a deeply -staining mass, apparently chromatin (x); 

 I think that this in a degenerated anaphase, the large staining mass 

 representing one metamorphosed chromosome plate, while a cor- 

 responding chromosome plate of the other clear cavity of the cell has 

 possibly been removed by the microtome knife. In Fig. 223, the three 

 bodies marked x seem to be abnormally large yolk globules. 



The foregoing observations point very strongly to the conclusion 



