Ce ae ee ee Te eee te et Cael Bee eee |e ee ae rene 
1903] GAMETOPHYTES AND EMBRYO OF TAXODIUM 5 
bent chromosomes and the inner ends of the latter are com- 
posed of four arms, lying side by side, and generally of the 
same length (jigs. 4-6). The second splitting has evidently 
occurred and the arrangement is now just as in Larix as 
described by Strasburger ('00). The chromosomes remain 
thick and short as they approach the poles, and their number 
can be easily determined to be either eleven or twelve. Eleven 
are shown in fig. 6 in polar view, and at least this number could 
be distinctly made out in other cases. Sometimes there seem 
to be twelve, but on account of the crowding in such cases I 
have never been sure of this number. Twelve chromosomes have 
been found by Belajeff (’94) and Strasburger (’92) in the pollen 
mother-cells of Larix europaea, by Blackmann (’98) in pollen 
mother-cells and oosphere of Pinus sylvestris, by Juel (00) in 
the megaspore mother-cell of Larix sidirica, and by Chamberlain 
(799) in the pollen mother-cells, endosperm, and jacket cells of 
Pinis laricio. It would thus seem from analogy that the number 
of chromosomes in the pollen mother-cells of Taxodium is also 
twelve rather than eleven. 
The daughter nuclei (fig. 7) before the next division enter 
into a fairly well-developed resting stage. There is a distinct 
reticulum, if indeed a rather coarse one, and the chromatin is 
grouped in larger masses than in the reticulum of many resting 
cells, approaching more nearly the condition already described in 
the nuclei of the tapetal layer of the microsporangium in Novem- 
ber. Strasburger (’00) describes such a condition in Larix, but 
tries to bring it in harmony with other cases by considering the 
network as spun out from the chromosomes. His distinction is 
not clear to me, and I think it must be acknowledged that the 
daughter nuclei of the first division may, at least in some cases, 
reach before their next division a relatively well advanced rest- 
ing stage. From fig. 7 it will be seen that the cell walls of the 
mother-cell have not disappeared at the time of tetrad-formation. 
In places the walls have begun to go to pieces, but in others 
fFemain entire and in close contact with their neighbors. No case 
was found where the final divisions were bilateral, as is some- 
times the case in Pinus Laricio (Coulter and Chamberlain, ’01). 
