GYMNOSPERMS, 165 
FECUNDATION. 
Goroschanken (’83) observed in Pinus pumilio that both male nuclei 
pass into the egg-cell, and the same fact was established for Picea 
vulgaris by Strasburger (’84). Dixon (’94) seems to have been the 
first to observe that in Pimus sylvestris all four nuclei in the pollen 
tube, z. e., the two male nuclei, the stalk-cell nucleus, and the tube 
nucleus pass into the egg-cell of the archegonium. This fact has been 
confirmed by Blackman (’98) for Pixus sylvestris, by Mutrill (1900) 
for Zsuga canadensis, and by Ferguson for Pinus strobus. Accord- 
ing to Blackman the behavior of the four nuclei in Pizus sylvestris 
can be easily followed after their entrance into the egg-cell. The two 
male nuclei around which the cytoplasm of the generative cell can be no 
longer observed are distinguished by their larger size. In P. strobus 
one of these nuclei is sometimes larger than the other (Fig. 68, C). 
The nuclei of the stalk cell and tube are, however, similar, and can 
scarcely be distinguished from each other. 
Within the egg one of the two male nuclei moves toward the nucleus 
of the egg, the other three nuclei remaining near the upper end of the 
cell. On its way through the cytoplasm of the egg the functional 
male nucleus increases in size, and in some cases in substances stain- 
ing more readily, but in others the increase in size seems to be due to 
vacuolation. The nucleus of the egg-cell in Pexus sylvestris at the 
time of fecundation presents a strikingly peculiar structure, which 
differs from that of the female nucleus in all other plants. After the 
formation of the ventral canal-cell the female nucleus migrates toward 
the center of the cell, and, by the time it has reached the middle, it 
has attained an enormous size, and there is developed within it a rather 
coarse, uniform, and wide-meshed linin reticulum which persists until 
a later stage (Fig. 69, A). Within this linin reticulum the chromatin 
is distributed in irregular masses of varying size. These masses may 
be in the form of irregular lumps as if composed of an aggregate of 
granules, or in shreds or rods with uneven edges. Sometimes they 
appear globular as small nucleoli. In fact it is quite difficult to distin- 
guish between some of the small nucleoli and similar chromatin masses, 
if, indeed, a difference really exists. The quantity of chromatin in the 
nucleus is proportionally very small. In addition to the linin reticulum 
there is also present a fine granular substance which appears to be 
evenly distributed in the nucleus or aggregated along the linin threads. 
In the former case the nucleus appears more uniformly granular, and its 
linin reticulum stands out less sharply. The structure of the egg- 
nucleus in Pixus sylvestris, as described by Blackman, agrees with 
