'lO 
Professor Pom mer on Lepidocarpon. 
me to be entirely in accordance with the observed facts; these 
points I propose briefly to reconsider here. 
Lepidocarpon , it will be remembered 1 , is a Lycopodiaceous 
fructification of Carboniferous age, remarkable for the seed-like 
character assumed by the mature megasporangia. 
This character depends chiefly on two facts: 
1. That in each sporangium only a single megaspore came to 
maturity, forming the prothallus within it, and occupying, 
like an embryo-sac, almost the whole of the sporangial 
cavity. 
2. That an envelope grew up from the sporophyll around the 
sporangium, completely enclosing it, except for a narrow 
crevice along the top. Further, all the evidence shows 
that the megaspore was retained permanently within the 
seed-like organ, which, like a true seed, was shed as a 
whole. 
The chief point to be noticed concerns the nature of the 
envelope or integument. Professor Bommer says (p. 134); “ Les 
sporanges.sont proteges par les bords de la sporophylle qui, 
en se repliant audessus d’eux, leur constituent une enveloppe close 
et resistante,” etc. 
This interpretation of the integument as consisting of the 
infolded edges of the sporophyll is one which I have considered in 
my paper, and rejected, on grounds which Professor Bommer has 
not dealt with in his review. My reasons were these : 
1. In the distal part of the sporophyll the lamina is clearly 
seen projecting laterally beyond the base of the integu¬ 
ment, which cannot therefore be identical with it 3 ; 
2 There is good evidence that the integument was closed at 
its proximal end (towards the axis) a condition which 
a mere infolding of the margins will obviously not account 
for. 3 
These important points appear to have escaped Professor 
Bommer’s attention, for he merely refers to the presence of 
1 Scott, Structure and Affiuities of Possil Plants from Palaeozoic 
Rocks ; IV. The seed-like Fructification of Repidocarpon. 
Phil. Trans. Roy. Soc. B. vol.. 194, 1901. See also Nicw 
PHYT0r.0Gi.ST, February 1902, for a review by F. W. O. 
2 Scott, 1 . c., p. 306, PL 4 b Pig. 13 - 
■1. c., p. 308 , PI. 43, Pig- 2 4- 
