EARLY EMBRYOGENY OF REBOULIA 
HEMISPHAERICA 
(WITH FORTY-SEVEN FIGURES) 
A. W. DUPLER 
Our knowledge of the development of the sporophyte of Reboulia 
dates back to HoFMEISTER (11), who described its early stages and 
its rapid growth as it approaches maturity. KreniTz-GERLOFF 
(13), who studied the embryogeny of a number of forms, claimed the 
Reboulia embryo to be similar to that of Grimaldia, certain stages 
of which he described in some detail, but not including the earliest 
stages. LritcGEB’s (14) work on the Marchantiaceae included a 
study of Reboulia, of which he described the development of the 
sporophyte in a general way. CAVERS’ (3) observations also in- 
cluded the early and late sporophyte of Reboulia. ‘The more recent 
work on the embryo has been done by WoopBurRN (18) and Haupt 
(10), the former dealing with the very early stages, the latter de- 
scribing the development from beginning to maturity. These two 
recent accounts differ somewhat from the earlier studies, and in 
certain features from one another. A study of the writer’s collec- 
tions of material has yielded certain results which may be of interest 
in comparison with these accounts, especially where they bear on 
their differences, and in the addition of certain facts not mentioned 
by them. Altogether it is clear that the embryo of Reboulia shows 
considerable variation in the early phases of its development. 
Material 
The material for this study was collected near Huntingdon, 
Pennsylvania, the greater bulk of the embryos figured having been 
secured from collections made from the early part of October to 
the latter part of November, 1919. None of the material collected 
in September shows embryos so far as it has been examined. The 
early winter condition (figs. 46, 47) was secured from a collection 
made December 23, 1920. The material was killed in 25 per cent 
chrome-acetic acid, and for the most part stained by the iron-alum 
143] [Botanical Gazette, vol. 74 
