BLACKMAN : THE SPERMATOGENESIS OF SCOLOPENDRA. 51 



during the metaphase the astral rays which extend through the cytoplasm 

 in the neighborhood of the spindle are very numerous and exceedingly 

 well developed, much more so than those which are directed toward 

 points nearer the poles of the cell. The latter are few and comparatively 

 inconspicuous. Each of the stronger fibres as it approaches the equatorial 

 region divides into several branches, slightly liner than the main 

 fibre, but still very definite and easily differentiated from the cytoplasmic 

 reticulum. These branches proceed through the dense outer layer of 

 cytoplasm and may be distinctly seen to come into contact with the cell 

 membrane. I believe there can be no reasonable doubt that they attach 



Fig. U. 



Fig. G. Diagramatic representation of a few of the astral rays in the meta- 

 phase. The fibres are much branched and cross in the equatorial region. The 

 branches come in contact with the cell membrane and probably are attached to it. 



themselves to this structure. I have never seen instances where the 

 peripheral astral rays from one pole unite and become continuous with 

 those of the other as is apparently the case with the spindle fibres. On 

 the contrary, it can be definitely seen that they behave in quite a different 

 manner. Each ray in the peripheral equatorial region is sharp and dis- 

 tinct, and in sections parallel to their course can often be traced from 

 their origin in the centrosome to their points of insertion in the cell 

 membrane. It can be very plainly demonstrated that during the meta- 



