136 ARCHEGONIATES. 
as in the Prerddophyta and gymnosperms, is a transformation of the 
entire contents of the cell, and we may with much propriety regard the 
spermatozoid of Chara and that of the fern as homologous structures. 
But whether we are dealing with real homologies, or only with striking 
analogies, is certainly a question concerning which there may be some 
diversity of opinion. 
The fate of the spermatozoid of Chara after penetrating the egg and 
the union of the two sexual nuclei is practically unknown in detail, and 
a further discussion of the process of fecundation in the absence of more 
facts would seem without value, since it is not the purpose to enter here 
into any discussion of the homologies of the sexual organs of the 
Characee with those of the Archegoniates. 
THE EGG-CELL AND FECUNDATION. 
In more recent years the process of fecundation has been observed 
in various genera of the Peléc?nee by Campbell, in Oxoclea by Shaw, 
and in Adzantum and Aspidium by Thom. ‘The author has followed 
the process in Oxoclea struthiopter?s, and his observations confirm 
those of Shaw, who has traced the behavior of the sexual nuclei in 
great detail in Oxoclea senstbilts. 
Soon after the division which cuts off the ventral canal-cell, and 
before the archegonium of Oxoclea struthiopteris is full grown, the 
three central cells contain fine-meshed and densely granular cytoplasm. 
Their nuclei are in the resting stage. The wall between egg and 
ventral canal-cell is generally arched slightly downward into the egg- 
cell. This wall is laid down in this position, at least in many cases, 
and the concave upper surface of the egg does not seem to be due to 
pressure from the ventral or neck canal-cell. 
As the archegonium matures it fcreases in size, and the cytoplasm 
of the central cells becomes looser. A rather large vacuole has been 
observed in the ventral canal-cell in the mature organ. It is well 
known that in Oxoclea the nucleus of the neck canal-cell often divides, 
but a division of the cell does not follow, except, possibly, in rare 
cases. The daughter-nuclei are reconstructed and lie usually close to 
each other. The author has observed in several instances that the 
division of the neck-canal nucleus took place at exactly the same time 
as the division of the central cell which cuts off the ventral canal-cell. 
Whether any special significance should be attached to this phenome- 
non the author is unable to state. Observers have often been tempted 
to consider the ventral canal-cell as a rudimentary egg, but if there be 
good grounds for such a view it is, perhaps, as much in harmony 
with the facts to regard the neck canal-cell or cells as aborted eggs. 
