Asexual Reproduction in Hepaticae. 155 
to the same would be, in the light of our present knowledge, 
incomprehensible. “The influence of the male nucleus on the 
fusing polar-nuclei is probably a necessary factor in the case, 
consisting in a stimulation of the female double-nucleus to further 
activity, by affording it a renewed supply of energy, while at the 
same time, as the experiments with the Maize appear to shew, 
characters from the male side are inevitably transferred to the 
regenerated megaspore-nucleus,” Celaskovsky states finally that he 
cannot admit that the originally normal process of fertilisation, the 
product of which is an embryo, has become degraded to a process 
of mere pseudo-fertilisation and the embryo to an endosperm- 
thallus, but must regard the new sexual act as phylogenetically an 
advanced process (“ Hoherbildung ”) ; for the original asexually- 
formed prothallus (in Pteridophytes, Gymnosperms, and possibly in 
many Angiosperms) becomes, in its second retarded stage (as in the 
case of certain, if not all, Angiosperms), sexually produced like the 
embryo. 
To our own mind, and as far as we can judge, the view set forth 
by Celakovsky affords a quite satisfactory solution of the whole 
problem ; it is nevertheless desirable that further observations of 
fact should be forthcoming. 
w. c. w. 
ON ASEXUAL REPRODUCTION 
AND REGENERATION IN HEPATICAE, 
By F. Cavers, 
Yorkshire College, Leeds. 
(With Eight Figures in the Text). 
(Continued from page 133 .) 
Gemmae. In the Acrogynae the gemmae, which are usually 
unicellular or few-celled, are formed from the cells of the leaf and 
sometimes also from the superficial cells of the stem. Not only 
the ordinary lateral or foliage leaves, but the amphigastria, the male 
and female bracts (“ perigonial ” and “ involucral ” leaves), and 
even the perianth may bear gemmae. The process of gemma- 
formation may be confined to the margin of the leaf or to the tips 
of the lobes in a divided leaf, or it may encroach more and more 
upon the tissue of the leaf, until the latter is represented only by 
a cluster of loosely-connected gemmae. In a considerable number 
of forms (c.g., Cephalozia bicuspidate , Kantia trichomanis), the apex 
