24 Lawson. — The Gametophytes, Archegonia, Fertilization , and 
As soon as the archegonia are mature and ready for fertilization, the 
two male cells move toward the wall of the pollen-tube and take up 
positions immediately opposite the necks of two neighbouring archegonia. 
The wall of the male cell and of the tube in the region opposite the neck- 
cells evidently become dissolved, for the nucleus of the male cell, with a 
very small amount of cytoplasm surrounding it, squeezes through the 
narrow canal between the neck-cells and immediately advances toward 
the egg-nucleus. During its passage through the canal the male nucleus 
becomes very much constricted and elongated, but as it approaches the 
egg-nucleus it soon resumes its spherical form. The denucleated male 
cell remains outside of the archegonium and retains its spherical form for 
some time after fertilization has been effected, when it becomes disorgan- 
ized. The nuclei of both male cells are functional, but they fertilize two 
neighbouring archegonia. 
At the time of fusion the sex-nuclei are of equal size, and as the male 
pushes against the female it becomes partially surrounded by the mem- 
brane of the latter. The chromatin of both nuclei are in the spireme stage, 
and when the membrane between the two breaks down, a common chro- 
matin network is formed in which the male and female elements can no 
longer be distinguished. 
Very soon after the complete fusion of the sex-nuclei the first cleavage- 
spindle is developed. There are no free nuclei formed in the pro-embryo. 
The first cleavage results in the formation of two distinct cells, each 
surrounded by a complete cell-wall. Both of these cells divide, so that 
the embryo now consists of a row of four cells. The lowest of these en- 
larges and divides again. The two cells resulting from this last division 
give rise to the suspensor and embryo proper. Each fertilized archegonium 
gives rise to but a single embryo. 
As near as could be estimated, there are sixteen chromosomes in the 
gametophyte and thirty-two in the sporophyte. 
In conclusion, I wish to express my sincere thanks to my friend 
Capt. C. B. Hudson, who assisted me in collecting material. 
Note. 
Since the above went to press Dr. Coker’s valuable work (1903) on 
Taxodium has appeared. I regret that it is too late to make a detailed 
comparison of Sequoia and Taxodium as worked out by Dr. Coker, as the 
two forms differ so widely in every essential detail. They should certainly 
be placed in different families. 
