Ber ridge. — Fertilization in Ephedra altissima. 5 1 1 
does occur seems probable from the fact that, more than once, five or six 
small nuclei are found in the egg-cell near the mouth of the pollen-tube ; 
also it is likely that the small nucleus associated with a male gamete, as 
represented in Fig. 13 of that paper, is really one of these secondary 
nuclei. 
In several archegonia fusion of the gametes was taking place at the 
time of the fixing of the ovule. In the preparation represented in Fig. 5 
the two nuclei although in contact are quite distinct. The male nucleus 
is closely granular in structure, and therefore appears darkly stained, the 
egg contains much larger fragments of chromatin material and shows 
a clear area just within the nuclear wall. No layer of dense cytoplasm 
is to be observed round the fusing nuclei, but they are surrounded by 
delicate radiations of the general cytoplasm of the egg-cell, which extend 
up to, and enclose the second sperm, which is more vacuolate and slightly 
larger than the first, probably because it has already begun to degenerate. 
These cytoplasmic radiations become more marked as fusion progresses, 
they also surround the daughter nuclei of this nucleus when they are first 
formed. The ventral canal nucleus still persists, though it also shows 
signs of degeneration. In another archegonium fusion of the gametes is 
almost complete, and here again no sheath of denser cytoplasm can be 
discerned, only a wide band of delicate radiating strands of cytoplasm. 
In this case the second male gamete has remained close to the neck and 
resembles the first gamete of Fig. 5 in its size and closely granular struc- 
ture. The ventral canal nucleus still persists as an irregular diffuse nucleus 
lying against the apical wall of the archegonium. 
Nothing like the post -fertilization activity of the jacket cells in 
E. distachya is to be observed in E. altissima ; the nuclei divide once by 
mitotic division as a rule, just after fertilization has occurred in the egg- 
cell, and then degenerate and die. 
A comparison of E. altissima with E. distachya emphasizes the 
abnormality of the latter ; it is hoped that a fresh gathering of ovules this 
season may determine whether this abnormal development in the latter 
is habitual or only due to adverse circumstances. 
Summary. 
The nucleus of the central cell of the archegonium divides and gives 
rise to a ventral canal nucleus very similar to the egg nucleus, but slightly 
smaller. This persists as a rule without degenerating till after fertilization 
has occurred. 
The body-cell of the pollen-grain divides into two equal gametes 
before the male gametophyte leaves the exine ; these travel down the 
tube enclosed in a cytoplasmic sheath. 
