40 BOTANICAL GAZETTE [JANUARY 
other chromosomes, have moved far from the equatorial plate. 
Fig. 26 also shows chromosomes in the anaphase lagging behind 
at the equator, while the majority have nearly reached the poles. 
CHROMOSOME NUMBER.—The metaphase of the second division 
represents the most favorable opportunity for the chromosome 
count. The chromosome number, however, was not determined 
with any finality. In diakinesis the chromosomes, though few 
in number, are so large that they obscure each other. A compari- 
son of the counts attempted during diakinesis and the second 
metaphase places the haploid number of chromosomes at either 12 
OF 54; 
Postsynapsis in the megasporangium 
The difficulty of obtaining maturation stages of the megaspore 
mother cell discouraged a study of meiosis in the pistillate material. 
Of the many slides prepared, the majority showed synapsis; in 
addition only a few postsynaptic stages were procured. The nuclei 
of the megaspore mother cells are larger than those of the micro- 
spore mother cells, and when desirable stages are found they are 
exceedingly favorable for study. 
The first stage noted after synapsis represents the nucleus as 
containing a mass of loosely interwoven filaments undivided and 
slightly beaded (fig. 28). The filaments thicken (fig. 29) and split 
longitudinally (fig. 30). Before the spireme breaks up into the 
bivalent chromosomes, it passes into strepsinema; the halves of 
the double filament draw apart, twist about, and cross each other 
(fig. 31). Attenuated portions of the spireme may be observed; 
transverse segmentation has begun and isolated pairs of chromo- 
somes may be seen near the periphery of the nucleus. 
In diakinesis the paired chromosomes occupy many positions 
with respect to each other, seldom lying strictly parallel. In 
fact, the description of diakinesis in the staminate loculus applies 
here. In fig. 33 several of the chromosomes offer a trace of a split, 
probably a precocious homotypic fission. In the microspore 
mother cells this split was not observed until the metaphase. 
This homotypic fission is described as occurring earlier in plants 
studied by the metasyndetists (Mottrer, Lewis, FARMER, DAVIS, 
