Far SOR tee ee Seer as ber ee Pe Me ee ates cool cree Se Se ORE Bo ot OR AO oa eee cmp oeea) aries eee 3 
oe to the micropyle under the i fluence o 
Principle of chemotaxis is a secretion from the synergids, it is 
ee interesting to observe that when the tube has reached and passed 
. the Synergids it is under the control of an influence powerful 
1897 | LIFE HISTORY OF LILIUM PHILADELPHICUM 417 
antipodal region of L. Martagon, shows that they might be taken 
for cases of mitosis. — 
In connection with the spindles of the embryo sac atten- 
tion should be called to the fact that the spindle fibers thicken 
in the equatorial plane as if preparatory to the formation of a 
cell wall (figs. rg, 75). This phenomenon has been taken to be 
another evidence of the descent of this free-celled gametophyte 
from one of compact tissue. 
The condition of things represented by fig. 77 is difficult to 
interpret. While it is no unusual thing for a partition wall to be 
formed at the antipodal end of the sac, a wall at the micropylar 
end seems worthy of comment. If the nuclear division repre- 
sented as just taking place is the first division of the definitive 
nucleus, which seems probable, the other nuclei are easily 
referred, and it would follow that the synergids are cut off from 
the oosphere (or oospore?) by a wall. 
In our preparations, the fusion of the polar nuclei is so com- 
monly associated with the fusion of the sex cells (jig. 7g) that 
the so-called « eight-celled”’ stage of the sac may be regarded 
as its ordinary ante-fertilization preparation. Figs. 78 and 79 
represent the fusion of polar nuclei, in the latter case but a 
small portion of the upper nucleus being shown. 
PHENOMENA OF FERTILIZATION. 
The pollen tube, as usual, passes between a ey and the 
wall of the sac, and then bends more or less sharply towards the 
Cosphere. Its enlarged caliber and more deeply staining con- 
tents are associated with the disorganization of the synergid 
with which it is incontact. If the pales sos has been directed 
xis, and the active 
