1 3 2 
Berridge and Sanday. 
cytoplasm. We seem to have here an exaggerated case of direct 
division, such as occurs in the jacket cells, where two nuclei often 
remain connected by a short narrow neck. In archegonia of similar 
age to this one, the egg and ventral canal nuclei are frequently 
irregular in shape and show a slight projection towards one another, 
such as might be produced by this mode of division. Such a pro¬ 
jection is well seen in the nuclei of a small archegonium shown in 
Fig. 8a ; here the resemblance to jacket-cell nuclei, such as the pair 
drawn in Fig. 8n, is very strong. They have not passed into the 
condition in which the archegonial nuclei are usually found at this 
time (similar to that described by Mr. Blackman as occurring in the 
egg-nucleus of Pinns sylvestris), with the chromatin aggregated in the 
centre, in the form of irregular masses or short thick bands. No wall 
is formed between the egg and the ventral canal nucleus* the latter 
lies freely within the oosphere, persisting until the archegonium is 
disorganized, or filled with pro-embryos. It can only be distin¬ 
guished from the egg-nucleus by its position near the apex of the 
archegonium, and by its somewhat smaller size. In this respect 
the species agrees with E. trifurca, but not with E. altissima , for in 
the latter, according to Strasburger’s account (6), a ventral canal 
cell is cut off by a wall from the oospere. It seems probable, 
however, that there is considerable variation within the genus in 
this matter, for among some sections of ovules of E. fragilis, var. 
campylopoda , one was found which shows at the base of the neck of 
a full grown archegonium a cell cut off from the egg only by a 
thickening of the cytoplasm, and not by a definite cell-wall (Fig. 9.) 
As the time for fertilization approaches, the apex of the arche¬ 
gonium appears to press upward into the neck, and in certain 
cases, probably where the entry of the pollen-tube is delayed, it 
grows towards the pollen-chamber, pushing its way through its own 
neck, as in Fig. 10, where the constriction at a evidently marks the 
original position of the apex. A similar growth of the apex of the 
archegonium through the neck has been noted by Coker in Cephalo- 
ta.xus fortunei (7). The adjacent cells of the neck become dis¬ 
organized, and form the mucilaginous sheath described by Jaccard, 
but in this case the disorganization does not extend to the jacket 
cells. 
III.—Fertilization. 
The pollen-grain germinates in the lower part of the micropyle 
and in the pollen-chamber; the extine splits along one of its 
longitudinal furrows and is soon cast off by the growing pollen- 
tube. In the young tube four nuclei can usually be distinguished, the 
