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AMERICAN JOURNAL OF BOTANY 
[Vol. 9. 
along them. Whether or not this telophase may be considered as throwing 
any light upon the telophase problem brought up by Digby (191 9) may 
of course be open to question. 
The four nuclei come to lie equidistant from one another, so that when 
the new walls are formed the resultant spores are arranged in tetrahedral 
fashion. Between them, more or less prominent sets of spindle fibers 
often appear. Sometimes these are very marked, at other times there 
is hardly a trace of them, so that when present they are probably function- 
less. The walls separating the spores are not formed until after the nuclei 
have entered fully upon the resting stage. They are all formed at one 
time, appearing at first as delicate cleavage planes, which later become 
thicker and more prominent. If cleavage begins at the surface of the 
cell, it passes to the center with great rapidity. I am inclined to believe 
that it may be brought about almost simultaneously everywhere in the 
planes where the walls are to form. There is no evidence that the walls 
develop centrifugally, by the formation of cell plates between the nuclei. 
No cell plates were observed, even in cases in which the spindles were 
most prominent, and there can be but little doubt that the division is 
the result of very rapid furrowing. 
Discussion 
The results of this investigation are of interest from the standpoint 
of nuclear cytology, and also because of their bearing upon problems in 
Oenothera genetics. We will first take up the cytological questions in- 
volved, and follow these with a brief consideration of the genetical sig- 
nificance of the results. 
Cytological 
Telosynapsis vs. Parasynapsis. One of the first questions that naturally 
arises during the study of maturation divisions concerns the arrangement 
of the chromosomes and the nature of the spireme thread. The evidence 
in this case seems to lead one to a telosynaptic interpretation. During 
the early heterotypic prophase, there is little to lead one to suppose that 
the chromosomes are undergoing synapsis. For the most part, the threads 
are unpaired. The occasional bits of parallelism to be seen at this stage 
are about as much in evidence as one would ordinarily expect in the trans- 
formation of a reticulum into a spireme. They are not sufficiently numer- 
ous or sufficiently extended to warrant one in considering them evidences, 
either for the synapsis of whole chromosomes, or for the fusion of the 
halves of split chromosomes. Although I have not been able to study 
the somatic telophases antecedent to the heterotypic prophase, the results 
which Sharp (191 3, 1920) has obtained from the study of Vicia and Trades- 
cantia will probably hold perfectly well in Oenothera franciscana also. He 
has found that the alveolation of the chromosomes in telophase is too 
irregular to be called a splitting, and that in prophase the chromosomes 
