518 SAx: FERTILIZATION IN FRITILLARIA PUDICA 
the male nuclei have escaped, as Welsford (14) has maintained 
is the case in Lilium. 
The male nuclei while free in the cytoplasm of the cells of 
the embryo sac usually do not have the appearance of motility 
(Fics. 1, 5, 7). However, the vermiform appearance of some of 
the male nuclei while free in the cytoplasm and in contact with 
the female nuclei, is certainly suggestive of motility (Fics. 1, 2, 
6, II, 13, 27, 30). It has been noted that the male nuclei, while 
in the pollen tube, are more or less coiled. Yet when seen part 
way to the nuclei with which they fuse, especially when the 
distances are long, the male nuclei are quite straight. The un- 
coiling is also slightly suggestive of motility. The male nuclei in 
contact with the egg and polar nuclei are seen to curve around the © 
latter, which suggests independent motility and movement on 
the part of the male nuclei. The large number of stages found 
at this time as well as the appearance of the male nuclei, suggests 
that their movement may be rather slow, perhaps a creeping 
amoeboid motion. It might be suggested that it is possible that 
the male nuclei may be conveyed to the nuclei with which they 
fuse, both by their own motility and by the streaming of the 
cytoplasm. 
It is quite certain that the upper polar nucleus and male 
nucleus in contact, migrate to the lower polar nucleus by cyto- 
plasmic streaming. In most cases the male nucleus has lost its 
vermiform appearance before migration. Moreover, it is found 
in contact at any side of the upper polar nucleus. The accumula- 
tion of cytoplasm around the migrating nuclei and the small 
amount left in the upper portion of the ‘‘Endospermanlage”’ at 
the time of triple fusion, is evidence that the two nuclei are very 
probably carried by cytoplasmic streaming (TEXT FIGS. 2, 3)- 
It has been suggested that the rapidity of movement of the 
male nuclei is evidence of their motility. Yet the migration of 
the upper polar nucleus with the male nucleus, which appears to 
be brought about by streaming, even though the latter have 
further to go, is observed quite as rarely as free male nuclei. 
The abundance of material showing the various stages leading 
to the complete fusion of the male and female nuclei, as well as 
the numerous examples of complete fusion and subsequent stages 
