1 8 Lawson . — The Gametophytes , Archegonia , Fertilization , dwa? 
tubes, this position is peculiar, as it suggests a case of the female organ 
seeking the male. 
Owing to the large number of archegonia present, and their peculiar 
arrangement around the pollen-tubes, fertilization is easily accomplished. 
When the archegonia are mature, that portion of the wall of the tube 
opposite the opening between the two neck-cells is the only structure inter- 
vening between the egg and the male cells. At this time the two male cells 
have become spherical and lie one behind the other in the tube, and take up 
a position near the wall which touches the neck of the archegonia. The 
nucleus of the male cell is very large, containing one or two large nucleoli, 
and a very regular network of chromatin. The latter is in the form of small 
spherical granules suspended on the threads of linin. The egg-nucleus is 
slightly different in this respect. The chromatin here is much more finely 
granular, and consequently does not stain as deeply as the male nucleus. 
The wall of the tube opposite the archegonium about to be fertilized 
apparently dissolves, for a small portion of the male cell now penetrates 
the archegonium by forcing the two neck-cells asunder, as shown in Fig. 29. 
Through the narrow communication thus established the male nucleus finds 
its way into the archegonium. As it squeezes through the narrow passage 
between the neck-cells, it becomes constricted and much elongated, as shown 
in Fig. 31, and immediately fuses with the egg-nucleus. It is a remarkable 
fact, as shown in Fig. 29, that only a very small amount of the cytoplasm of 
the male cell enters the archegonium. After the discharge of the nucleus 
into the archegonium, the greater part of the male cell remains outside and is 
discarded. As far as I am aware, such a condition has never before been 
reported for any of the Conifers, and it goes to establish the generally 
accepted view that the essential thing in fertilization is the fusion of the 
nuclei. As shown in Fig. 29, the denucleated male cell retains its spherical 
form, but has a vacuolated appearance in the central region once occupied 
by the nucleus. The section immediately following the one from which this 
figure was drawn showed the nucleus of this male cell in the act of fusing 
with the egg-cell in the archegonium. An examination of a large number 
of preparations has convinced me that this is the typical method of fertiliza- 
tion in Sequoia sempervirens. For some time after fertilization has been 
affected, the denucleated male cell is invariably found in the tube outside of 
the archegonia. Even as late as the early stages of development of the 
embryo, shrunken fragments of it were found. According to Coulter and 
Chamberlain (1901), nearly the whole of the contents of the tube in Pinus 
is injected into the cytoplasm of the egg. Goroschankin (1883) reports that 
both male cells pass into the archegonium, and Strasburger (1884) finds 
a similar occurrence in Picea vulgaris . In Pinus silvestris , Dixon (1894) 
and Blackman (1898) find that all the structures present in the pollen-tube 
pass into the egg. This has also been observed by Ferguson (1901) in 
