386 
CLIFFORD H. FARR 
the number of chromosomes in MagnoHa is not given in this paper, 
but the series of stages are incidentally employed in determining the 
sequence of cytoplasmic phenomena, it is scarcely possible to doubt 
the validity of such stages as the formation of the dispireme (figs. 3 
and 20), its transformation into the prochromosomes (figs. 3-5, 20-22), 
etc. The two series of nuclear and cytoplasmic changes seem to be 
remarkably constant in paralleling each other. Only during the 
interkinesis are any cases of possible lack of correspondence found. 
The photomicrographs and drawings given herewith show very clearly 
the simultaneous nature of these phenomena. 
The number of chromosomes can be determined most easily by 
a study of the polar view of the metaphase of the homoeotypic division 
(fig. 9). The following are the results of counts made on a few cells: 
45, 46, 45, 43. A fifth cell appeared to have more than any of these, 
but this was probably due to confusion of the two parts of the same 
chromosome and to difficulty in determining in each case whether they 
were pairs or only single chromosomes. The gametophytic number 
of chromosomes thus seems to be about 45. 
The stages up to the telophase of the first meiotic division were 
described by Guignard (8) and will not be further discussed here. 
After the anaphases of the heterotypic karyokinesis the chromosomes 
assemble at the poles in the usual fashion and a nuclear membrane is 
formed, organizing a nucleus which is flat and discoid (figs. 2 and 26). 
The spireme is next formed from the chromosomes (figs. 3 and 20). 
At this time a streak appears midway between the two nuclei in exactly 
the position in which a cell plate might be expected. This streak takes 
the orange stain in Flemming's triple combination. Timberlake (16) 
in his study of cell division in the root tips of onion and the pollen 
mother cells of larch showed that such an "orange zone," as he called 
it, precedes the formation of the cell plate, and interpreted it as a pre- 
liminary step in cell-plate formation. In Magnolia it seems that the 
orange zone appears, but in no case is there any evidence of its being 
followed by the formation of a cell plate. It must be that the condi- 
tions for cell-plate formation obtain at first, but that they do not con- 
tinue to exist, or that some factor enters in to interrupt the process. 
I was able to find this orange zone in only five or six out of fifty or 
more cells of Magnolia which, judging from the nuclear phenomena, 
were in exactly the same stage. It is thus by no means certain that it 
is formed in the division of every mother cell. Neither Andrews (i), 
