SAX: FERTILIZATION IN FRITILLARIA PUDICA 519 
in the division of the fertilized egg, leaves no doubt that at least 
in Fritillaria pudica the complete union of the male and female 
nuclei actually occurs. The rare appearance of such cases as that 
of the spireme stage in the egg and male nuclei when their outlines 
are still distinct, is probably of little significance in this respect. 
It is probable that these nuclei subsequently fuse completely 
because no later stages of incomplete fusion were found. If the 
adjacent walls of these two nuclei are not broken down, it would 
suggest that the fusion of the two sexual nuclei is not necessary 
to stimulate the formation of the early stages in division. This 
suggestion is supported by cases found in the Gymnosperms by 
Miss Ferguson and others. 
From the many stages and abundant cases of triple fusion, 
there is no doubt that the two polar nuclei and the male nucleus 
fuse completely and that the subsequent division is normal. In 
this fusion there are at least twice as many female as male chromo- 
somes. If this phenomenon of a normal triple fusion holds true 
for plants whose hybrids show a Mendelian ratio in endosperm 
characters, then an interesting question arises as to the distribution _ 
of the characters among the chromosomes. 
SUMMARY 
The results obtained from the study of fertilization in Friti- 
laria pudica may be summarized as follows: 
1. In the mature embryo sac of Fritillaria pudica the egg cell 
cannot be distinguished from the other two cells of the egg ap- 
paratus. The ‘‘Endospermanlage” extends up between and 
around the cells of the egg apparatus. 
2. The pollen tube usually turns along the outer wall of the 
nucellus or embryo sac before entering. At this time the cells of 
the egg apparatus are all intact. 
3. The pollen tube practically always enters and at least partly 
destroys one synergid. 
4. Although a distinct appearance of motility is evident in 
Many male nuclei, the majority do not suggest much motility. 
5. The male nucleus and the egg nucleus fuse completely 
before division. 
6. The upper polar nucleus, with the male nucleus in contact 
