CHAPTER VI.—ARCHEGONIATES. 
The preceding chapters have been devoted to the process of fecun- 
dation in various typical and well known Thallophyta, with the 
exception of the Characea, if we may speak of this group as belonging 
properly to the Zhallophyta. Owing to the closer resemblance of 
both sexual organs and gametes to those of certain Archegoniates, it 
has been deemed best to refer to the Characee in connection with 
those plants. 
Because of our meager knowledge of the development of the sperma- 
tozoids, and the union of the sexual nuclei in liverworts and mosses, I 
have omitted a discussion of the process in these groups and have dealt 
more fully with sexual reproduction in certain Pteridophyta and 
gymnosperms. 
The discovery of spermatozoids in Cycas by Ikeno and Hirase, and 
in Zamia by Webber, and a more accurate knowledge of the develop- 
ment of these structures in the Péer¢dophyta have aroused an unusually 
keen interest in the study of the sexual cells and the phenomena 
accompanying their union both in these and in the higher plants, In 
presenting the phenomena relating to the sexual process in the Arche- 
goniates, we shall confine ourselves largely to Onxoclea and Gymno- 
gramme among the Pteridophytes and to Cycas, Zamia, Ginkgo, 
and Pinus of the gymnosperms; for it is in certain species of these 
genera that the process, in so far as it has been followed with the use 
of later methods of research, is best known. 
PTERIDOPHYTA. 
Until recently the spermatozoid of the Pterddophyta was generally 
conceded by many of the most competent investigators to consist 
merely of a transformed nucleus with cilia of an obscure cytoplasmic 
origin. This view was due very largely to the methods of fixing and 
staining used, which, as we now know, were inadequate to bring out 
with definite clearness the more delicate cytoplasmic structures of the 
cell. ; 
In recent years Belajeff, Shaw, and others have applied improved 
cytological methods to the study of the development of the sperma- 
tozoid in Gymnogramme, Onoclea, Marsilia and Egutsetum. In 
certain species of these genera, they have found that the mature 
spermatozoid consists of a nucleus and a delicate band or wing of 
