434 



HISTOLOGY 



FIG. 388. Anaphase of first reduction division in 

 Magnolia. X 1800. 



At the same time an equatorial band of darker material appears in the 



cytoplasm surrounding the nucleus (Fig. 386, d.m.}\ this band is cut at 



two points and the sections 

 appear as two roughly 

 crescentic lines of some 

 width and tapering to 

 blunt points. The chro- 

 matic material has mostly 

 left the nucleus and been 

 added to the chromatin 

 particles which have now 

 become larger, more uni- 

 form in size, and are 

 evidently the future chro- 

 mosomes of the first reduc- 

 tion divisions. They 

 appear in the next stage 

 represented (Fig. 387) in 



their regular size, shape, and arrangement, and the fibrils have been 



arranged into the familiar spindle which here is gathered distally 



into several points near together. The dark cytoplasm material is now 



increased to form a complete shell about the whole figure which is just 



beginning to divide its chromatin. 



Figure 388 shows the division half done, and again shows the differen- 

 tiation of mantle and spindle fibrils. The spindle fibrils seem to be fewer 



in this stage than in a 



later one (Fig. 389), 



where they are very 



numerous, and have 



already begun to show 



the equatorial plate that 



marks the position of 



the cell's final division. 



The chromosomes are 



still separate and are 



somewhat fused. The 



dark zone of cytoplasm 



is diffused and shows 



but a trace of its 



former presence FIG. 389. Late anaphase of first reduction division in 



Radiating aster-like 



rays reach from the chromosome masses out into the cytoplasm. 

 In Figure 390 the two nuclei are re-formed and have acquired a very 



