The Prothallus of Lycopodium clavatum, L . 1 
BY 
WILLIAM H. LANG, M.B., B.Sc., 
Lecturer in Botany at Queen Margaret College , and Clark Scholar , 
University of Glasgow. 
With Plates XVI and XVII. 
I N no group of the Pteridophyta has information regarding 
the life-history been accumulated more slowly than in 
the case of the Homosporous Lycopodiaceae. Both sexual 
and asexual generations are now known, however, in several 
species of the genus Lycopodium. Had the prothalli of these 
been found to resemble one another as closely as is the rule 
in the other genera of Vascular Cryptogams, comparatively 
little interest would attach to the investigation of the remaining 
species. But among them several distinct types of prothallus 
1 Sinee the manuscript of this paper was completed, an important monograph 
by Professor Bruchmann (Ueber die Prothallien und die Keimpflanzen mehrerer 
europaischen Lycopodien ; Gotha, 1898), dealing with the prothalli and young 
plants of Lycopodium clavatum , annotinum , complanatum , and Selago, has been 
published. The facts contained in this are considered along with the other 
knowledge we possess of the gametophyte in this genus, in the concluding portion 
of the present paper, but the earlier part has been left untouched, save by the 
addition of a few notes referring to Bruchmann’s observations on the same species. 
I may therefore take this opportunity of pointing out that the description of the 
facts, though founded on independent observations, must for the most part be 
regarded as confirmatory of the account previously published by Professor 
Bruchmann. 
[Annals of Botany, Vol. XIII. No. L. June, 1899.] 
