OOGENESIS IN PINUS LARICIO, 
WITH REMARKS ON FERTILIZATION AND EMBRYOLOGY, 
CONTRIBUTIONS FROM THE HULL BOTANICAL 
LABORATORY. XIV. 
CHARLES J. CHAMBERLAIN. 
(WITH PLATES IV-VI) 
In the autumn of 1896, while conducting laboratory work in 
the special morphology of the gymnosperms, I noticed puzzling 
peculiarities in the development of the nucleus of the oosphere, 
but the material lacked important stages and had not been prop 
erly fixed for cytological study. The next spring, however 
at intervals of three or four days, ovules of Pinus Laricio Poit 
were collected which gave a fairly complete series from the sep 
aration of the neck cell from the central cell of the archegonlum 
up to stages in which the embryos had been thrust through 
the base of the oospore by the elongating suspensors. 
For the earlier stages up to the cutting off of the ventral 
canal cell, the pair of ovules was merely cut off from fale 
and dropped into the killing fluid; for stages from this po! 
to the fusion of the pronuclei, the female gametophyte si 
thallium) was usually removed from the ovule to insure wt 
killing and fixing. Ina part of the material, however, the a 
lus was retained to show the course of the pollen tube vs 
oosphere. In all the later stages the gametophyte was pe 
from the ‘ovule. All material was fixed on the spot, no tree 
being taken from cones which had been removed from the nty 
for more than fifteen minutes. In some cases aS Many pe 
ovules were taken from a single cone and kept im 4 ne 
bottle. These showed almost an identical stage of phe cones 
This uniformity occurs also in the sporangia of ie 
in which the pollen mother cells undergo division at ly 00 
same time, the sporangia at the base being only slig fart 
268 
