1913] PACE—APOGAMY IN ATAMOSCO 381 
An endosperm tissue 2~4 cells in width, but which does not com- 
pletely fill the sac, and with many free nuclei still present, is found 
with the embryo of 30-40 cells. There is such a mass of long curved 
chromosomes in the endosperm that no satisfactory count could be 
made from any of my preparations. In several instances one could 
count 50 and know there were still others. One such nucleus, 
which. was in three adjacent sections, is shown in figs. 26, 26, a, 
and 26, b. It seems clearer to show each section separately than 
to reconstruct the nucleus from the three sections. Here more than 
60 chromosomes can be counted in all three sections, but it is certain 
that there were several cut chromosomes, as some were evidently 
shorter than others, and in this plant the chromosomes all seem to 
be approximately the same length. The number would be 60 from 
the fusion of two polars with 24 each and a sperm nucleus with 12. 
It is possible that.in some cases the polars only enter into the fusion, 
which would give 48. But the triple fusion seems the common 
condition in the material examined. This is probably the fourth 
division of the endosperm of this sac. These divisions are not 
always exactly simultaneous; for in one instance in the second 
division one nucleus has completed the mitosis, the new nuclei being 
already perfect, while the other nucleus was still in the anaphase. 
Embryo 
The embryo shows nothing unusual in its development. The 
first division has already been described, and is shown in figs. 20-24. 
One two-celled embryo was seen with a vertical wall, but in all 
others it was the usual horizontal wall (fig. 27). This figure shows 
the pollen tube entering one synergid. 
Abnormal sacs 
Atamosco also has many sacs in which the arrangement of the 
nuclei does not follow the usual form. These sacs have the antipo- 
dal group in the micropylar end of the sac and egg apparatus at 
the side. The organization of the two groups of cells is as perfect 
and as characteristic as if they were in the usual position. About 
2000 ovaries have been cut; many were too young to show mature 
sacs, and of others no record was kept. But in about 300 ovaries 

