THE MALE RECEPTACLE AND ANTHERIDIUM 
OF REBOULIA HEMISPHAERICA 
A. W. DUPLER 
(Received for publication October 28, 1921) 
The genus Reboulia has received less attention from morphologists than 
certain other forms of the Marchantiales, although recent papers by C. 
and R. Douin (10), Woodburn (29), and Haupt (16, 17) give evidence of a 
present interest in the form. The writer has shared in this interest and for 
some time has had in progress a study of R. hemisphaerica (L.) Raddi with a 
view to securing as complete an account of its morphology as a large collection 
of material would afford. The results of the writer's study of the origin and 
structure of the air chambers have been recently presented (11). Haupt's 
account is the only critical study of the sex organs to date, and should 
receive due credit as such. The following account of the antheridial struc- 
tures confirms the work of Haupt in some features and supplements it in 
others. 
The material used in this study was for the most part collected from the 
lower margins of a north-exposed talus slope at the base of a steep shale 
cliff, near Huntingdon, Pennsylvania, at intervals from 1912 to 1920. A 
second group of material was secured from near Mount Carroll, Illinois, 
in January, 191 6, and kept in good growing condition in the botanical green- 
house of the University of Chicago. The last collection from this material 
was made in August, 191 6. Under field conditions antheridia develop 
during the latter part of the summer, especially in August. In the green- 
house cultures antheridia were forming as early as April, although the 
August collections also showed antheridial receptacles in early stages of 
development. 
Historical 
The early study of Reboulia was concerned with its taxonomic features. 
Micheli (24) gave good figures of the male disc, describing the plant as 
''Hepatica media capitulo hemispherico.'' Bischoff (i) noted the median 
or terminal position of the flat receptacle and the erect antheridia imbedded 
within its tissue. Hofmeister (18) observed the mature antheridium, claim- 
ing the tabular wall to be supplanted toward maturity by a membranous 
sac. He cites and figures the male receptacle directly behind the female 
receptacle. His suggestion that it is "probable that these [antheridial] 
cushions may be weakly developed shoots" is of interest. Leitgeb (21, 
22) regarded the receptacle as a dorsal outgrowth, not involving the thallus 
apex in its formation, but in cases when the apex is permanently checked 
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