Fertilization in Ephedra altissima. 
BY 
EMILY M. BERRIDGE, B.Sc., F.L.S. 
With Plate XXXVI. 
I T is somewhat remarkable that, although the development of the pro- 
thallium and archegonium in three species of Ephedra , E. Helvetica , 
E. trifurca and E. distachya , has been very fully described, and the 
embryogeny in the first two carefully investigated, our knowledge of 
the important intermediate stage, that of fertilization, is still very imperfect. 
In the two cases of fertilization observed by M. Jaccard 1 and Dr. Land 2 
the fusion of gametes is so advanced, that the individual nuclei are 
almost indistinguishable ; moreover, in the figure given by the latter, 
the smallest nucleus, interpreted as the ventral canal nucleus, is evidently 
the second male, while that which more nearly approaches the egg in 
size is certainly the ventral canal nucleus. 
It therefore seemed desirable to give a short account of some pre- 
parations obtained from ovules of E. altissima , illustrating the period of 
development from the germination of the pollen- grain and the separation 
of the ventral canal nucleus to the formation of the fusion nucleus. 
The ovules were gathered, by kind permission of Lady Hanbury, in 
the garden of La Mortola, near Ventimiglia ; most of them were fixed 
in acetic alcohol and stained with Heidenhain’s iron haematoxylin. The 
material was collected on March 9, 11, and 12, but as it was obtained from 
five different plants in varying stages of development, a close series was 
secured. By March 13 all the fertilized ovules contained embryos. 
The organization of the ovule in E. altissima before division of the 
central nucleus is almost identical with that of E. trifurca , as described by 
Dr. Land. The nucleus, which is closely applied to the apex of the 
archegonium, is large and contains a considerable amount of chromatin 
material collected in the middle, with a clear space surrounding it ; the 
nucleolus also is large and prominent. 
1 P. Jaccard : Recherches embryologiques sur V Ephedra helvetica. Bulletin de la Societe 
Vaudoise, xxx, 1894. 
2 W. J. G. Land : Fertilization and Embryogeny in Ephedra trifurca. Bot. Gaz., xliv, 272-290, 
1907. 
[Annals of Botany, Vol. XXIII. No. XCI. July, 1909.] 
