48 PHARMACEUTICAL BOTANY 
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Fic. 25.—Semi-diagrammatic representation of nuclear and cell-division. a, 
resting cell ready to begin division; 6, the nuclear reticulum is assuming the form 
of a thickened thread, and the cytoplasm at opposite poles is becoming thread- 
like to form the spindle fibers; ¢,the nuclear thread has divided longitudinally 
through the middle, and the spindle fibers have become more definite; d, the 
nuclear membrane and the nucleolus have disappeared, and the nuclear thread 
has become segmented into chromosomes which are assembling at the equator of 
the cell. All of the phases of division thus far are called prophases. e¢, the meta- 
phase, where the longitudinal halves of the chromosomes are being drawn apart 
preparatory to their journey toward the opposite poles; f, the anaphase, or move- 
ment of the chromosomes toward the poles, is about completed, connecting fibers 
extend from pole to pole; g, telophase where the chromosomes have begun to spin 
out in the form of a nuclear reticulum. The connecting fibers have begun to 
thicken in the equatorial plane; A, the connecting fibers have spread out and come 
into contact with the wall of the mother cell in the equatorial plane, and the 
thickening of the fibers throughout this plane has made a complete cell plate 
within which the dividing wall will be produced; 7, a nuclear membrane has been 
formed about each daughter nucleus, and the dividing cell-wall is completed. 
The two daughter cells are now ready to grow to the size of the parent cell in a, 
when the daughter nuclei will appear as does the nucleus there. All highly mag- 
nified, (Stevens.) 
