28 o 
Ethel M. Berridge. 
wall. Dr. Land regards this tissue-formation as the result of the 
disintegration of a certain nucleus lying near the apex of the 
archegonium, which he considers to be the second male nucleus, but 
which from its position and size, appears extremely like the persistent 
ventral canal-nucleus frequently found in other species of Ephedra. 
For the first or functional male-nucleus is distinctly smaller than 
the ventral canal-nucleus, and the second male-nucleus is certainly 
not larger than the first. The latter was identified in the slides 
made by Miss Sanday for a previous paper in this Journal (2) in five 
separate cases, once close to the egg-nucleus, twice well on its way 
toward the latter, and twice near the tip of the pollen-tube ; it is 
only 8 to 13/x in mean diameter, while that of the ventral canal- 
nucleus varies from 19 to 30/x. The size of the male-nuclei is 
therefore comparable with that of the generative nuclei in Angio- 
sperms ; in this respect the Gnetaceae may show a Pro-angiospermic 
character. The fact certainly accounts for the difficulty, experienced 
by all investigators, in identifying with any certainty cases of actual 
fusion of the gametes in this group. 
But whether this evanescent “ physiological endosperm” des- 
scribed by Dr. Land be produced by the interaction of the chromatin 
of disintegrated jacket-nuclei with that of the second male nucleus 
or is merely a complicated example of nuclear disintegration such as 
was observed by Murrill in Tsuga canadensis , a view suggested by its 
occurrence in cells other than the archegonium, it is distinctively a 
degenerative tissue, and hardly likely in the course of evolution to 
replace, as a nutritive tissue, the jacket and prothallial cells which 
at this time are showing signs of renewed activity and vigour. 
It must be admitted, however, that it is closely associated with 
a process of pro-embryo formation from which, as I hope to show, 
the endosperm of the Angiosperms may have originated. 
An objection on somewhat similar grounds may be urged 
against the theory lately brought forward by Dr. Otto Porsch (3), in a 
lengthy communication consisting to a great extent of a summary 
of recent work on the Gymnosperms, together with a few original 
observations on Ephedra distachya. He regards the embryo- 
sac as homologous with two fused archegonia each consisting of a 
tetrad of nuclei, i.e., two neck-cells, an egg-cell, and a ventral canal 
nucleus. Practically the same view was brought forward by 
Professor Hartog in 1891 (4), though expressed in somewhat more 
general terms. The synergidae and the two lower antipodals are by 
this author regarded as neck-cells of reduced archegonia, and the 
