SAX: FERTILIZATION IN FRITILLARIA PUDICA 507 
that the sexual nuclei do not completely fuse but form inde- 
pendent spindles in close proximity to each other. 
The material for the present study was collected near Pullman, 
Washington, in April and May, 1914 and 1915. Fritillaria pudica 
Spreng. is exceptionally good for the study of the process of 
fertilization because it seeds so freely. In many ovaries practically 
every sac contained a stage in fertilization. In several ovaries 
stages were found from synapsis of the megaspore mother cell to 
stages in fertilization. In the material cut and stained I have 
found not less than two thousand cases of double fertilization at 
various stages. 
Strong chrom-acetic acid and Flemming’s stronger solution 
were used as fixatives. Most of the sections were cut 10 u thick, 
but a few were cut 15 » and 20y. They were stained with modi- 
fications of Flemming’s triple stain and with safranin and Licht- 
griin. Good results were obtained with all stains used. 
Although the development of the ovule has been traced from 
the stage containing the megaspore mother cell up to the time 
when the young embryo and endosperm are formed, this paper 
will deal largely with fertilization. Other processes of interest 
will be dealt with in a later paper. 
The mature embryo sac of Fritillaria pudica contains the egg 
and two synergids at the micropylar end, and one normal anti- 
podal cell and one which is disorganized at the chalazal end. 
Between these groups of cells is the ‘‘Endospermanlage”’ of 
Nawaschin, which contains the two polar nuclei, the upper one 
near the egg apparatus, the lower one near the antipodal end. 
There are thus usually but seven nuclei in the mature embryo 
sac. The one nearest the chalazal end is at least partly dis- 
organized. The lowest of the four nuclei resulting from the 
second division usually fails to divide. The three cells of 
the egg apparatus are somewhat pear-shaped and arranged sym- 
metrically in the upper end of the sac. They are usually very 
much alike in size and appearance and it is very doubtful if the 
egg can be distinguished from the other two cells until the time 
of fertilization. They are bounded by very delicate membranes, 
