196 
F. Cavers. 
occupying different portions of the same receptacle, occur in Mono- 
selenium. In this peculiarity the genus resembles Dumortiera , 
though androgynous receptacles occur also in Preissia and have 
recently been described by Cutting 1 in a species of Marcliantia. 
The occurrence of these “ abnormal ” receptacles is of interest from 
various points of view ; for one thing, they demonstrate the homology 
which exists between the male and female receptacles throughout 
the Marchantiacese, and which could otherwise be inferred only from 
the facts of comparative morphology. 
1 Cutting, E. M. “On Androgynous Receptacles in March anti a." 
Annals of Botany, vol. 24, 1910, pp. 349-357. 
