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BOTANICAL GAZETTE 



central body, appear to be pushed back on either side by the interior 

 expansion of the mass, finally to take up a position at the poles of 

 the spindle (rigs. 15, 16). 



Prophase fixed 



Since each preparation could exhibit only the particular phase 

 of activity at the instant of fixation, and since this period averages 

 15 minutes, it would be difficult to find two series of precisely 

 equivalent stages. The differences manifested upon fixation of the 

 turbid spherical mass can best be explained by references to the 

 figures. These all show with the enlargement of the nucleus the 

 unequal increase of the suspensors as the spindle begins its evolu- 

 tion. In all of the cells the beginning of the formation of the cell 

 plate is to be seen before the dissolution of the nuclear membrane. 

 No attempt is made to present the figures in sequence, as there is 

 no evidence as to whether one stage follows another or as to whether 

 in other nuclei a different disposition of substance may not obtain 

 at corresponding intervals of divisions. 



The chromatic granules, as in fig. 28, may be scattered on the 

 main suspensor as well as over the central mass of granules. All 

 of the chromatic substance may be gathered in a sphere to one 

 side of the enlarged nucleus. This substance is in the form of 

 granules (fig. 27) or of filaments and granules (fig. 25). In fig. 26 

 chromatic granules are connected by a finer network and distrib- 

 uted all over the enlarged nucleus. In the center lighter granules 

 may be seen, suggesting a decomposing nucleolus. Fig. 29 shows 

 lighter stained granules equally distributed over the mass. Scat- 

 tered among them are short filamentous bodies. Finer granular 

 masses in the center indicate the remains of a nucleolus. In 

 figs. 31 and 33 is seen a somewhat contracted spherical mass, evi- 

 dently both nucleolus and nuclear plasm, and consisting of granules 

 both lightly and deeply stained. These are connected with the 

 nuclear membrane by delicately stained strands. This and fig. 25 

 might be considered as a stage in synapsis. In fig. 24 no finer 

 granular material is seen within the nuclear membrane, but there 

 are chromatic masses ranging from tetrahedral forms to that of 

 vesicles. Fig. 35 shows similar chromatic masses imbedded in or 



