The Gametophytes and Fertilization in Laminaria 
and Chorda. (Preliminary Account.) 
BY 
J. LLOYD WILLIAMS. 
I N the study of artificial cultures of germinating spores of members of 
this group of Algae, one always observed the presence of a much 
smaller brown alga along with the undoubted cells or cell-chains that gave 
rise to the laminarian plants. As the terminal cells of the branches of the 
smaller alga were frequently found to be empty, the idea suggested itself 
that they were the antheridia of the male gametophyte. 
Until recently all attempts at verifying this conjecture by observing 
the liberation of the contents and the process of fertilization failed. To 
Sauvaugeau belongs the credit of finding the first piece of evidence in favour 
of the correctness of the above suggestion. Although he, also, failed to 
find actual liberation of male gametes and fertilization, he was lucky enough 
to find in Saccorrhiza abnormal cases of germination of zoospores within 
liberated but unripe sporangia. In these cases the resulting growths were 
of two kinds, and similar in every respect to the two always found in 
normal cultures. This made it almost certain that the smaller alga, which 
had appeared so puzzling, was also derived from zoospores of Saccorrhiza , and 
consequently must be the male gametophyte. The writer of this article 
did not feel himself justified in publishing his own detailed study of the 
group until he had seen and studied the actual liberation of antherozoids 
and the process of fertilization. That this is a very difficult task will be 
evident when we consider the microscopically small size of the game- 
tophytes, the fact that all the stages must be followed in artificial cultures, 
and that, in consequence of the time taken in maturing (varying from a few 
weeks in Laminaria to many months in Chorda ), the sexual cells are 
liberated, one or a few at a time, with long intervals between. It will be 
evident that the chances are very much against one being fortunate enough 
to see these stages at the critical time. Even continuous observation 
would not suffice to guarantee success, for fertilization may be taking place 
on a slide while it is being examined under the microscope, yet owing to 
the smallness of the objects the observer may miss it completely. The 
[Annals of Botany, Vol. XXXV. No. CXL. October, 1921.] 
