BLACKMAN : THE SPERMATOGENESIS OF SCOLOPENDRA. 61 



in various parts of the cell, and when this occurs the present condition 

 of the cytoplasm no longer exists, the network becoming much coarser 

 and more transparent (compare Figs. 78, 79 with Figs. 8G-94). 



In the telophase of the last spermatocyte division the two daughter 

 cells, even when incompletely separated by the constricting membrane, 

 seem to exhibit a mutual repulsion, as shown in Figure 77 ; this causes 

 them to separate from each other as far as the persisting remnants of 

 the spindle will allow. As in the first spermatocyte division, the dark 

 bodies which form a band around the outside of the spindle sheaf at its 

 middle lie entirely outside of both the resulting cells. This is quite evi- 

 dent in Figure 77, but is even more marked at a later stage (Fig. 78). 

 Here a great part of the Zwischenkorper is outside the cell, and in many 

 cases at least, it is all eventually detached in a manner similar to that 

 which occurs in the first spermatocytes (Plate 3, Fig. 41). As a result 

 of this process, spermatids are produced (Figs. 79 et seq.) which con- 

 tain no trace of a true " Nebenkern " at any stage, although a structure 

 similar to it, which by many writers has been confounded with the 

 Nebenkern appears at a later stage. That the archoplasmic structure 

 seen in the spermatid at the time the axial filament is forming is not the 

 Nebenkern, is shown by the bodily casting off of the remnants of the 

 spindle and by the fact that for a' considerable period thereafter no 

 such structure is to be seen in the cell (Figs. 78-84). 



Thus the spermatid, soon after it has become free from its mate by 

 the destruction of the connecting bridge of interzonal filaments, presents 

 the appearance represented in Figure 79. The cytoplasm is of the fine- 

 meshed character noted above and is entirely free of any special aggrega- 

 tions of archoplasm. The centrosome still retains its peripheral position 

 and lies in close contact with the cell membrane. There is no centro- 

 sphere or other similar aggregation of archoplasm around it, but only 

 very faint traces of the disintegrating astral rays in the last stages of 

 dissolution. 



The nuclear vesicle is considerably enlarged, although still much 

 smaller than it later becomes. The chromatin is much more diffuse 

 than formerly, and the most of the chromosomes are situated at the 

 periphery of the nucleus. They have the form of ovoid granular bodies 

 often flattened in the plane of the nuclear membrane. From these 

 bodies very definite deeply staining granular processes extend out and 

 connect with similar ones from other chromosomes (Fig. 79). These 

 processes stain with the same intensity as the chromosomes and are 

 doubtless composed, at least in part, of chromatin. 



