6 ERNST ANTEVS, LEPIDOPTERIS OTTONIS (GÖPP.) SCHIMP. AND ANTHOLITHUS ZEILLERI NATH. 
As has been mentioned, the epidermal structure of the lamina (pl. 2, figs. 1—4, 
10) agrees with that of the rachis. "The whole surface is unvaried with the exception 
that the stronger veins — midrib and lateral veins in a pinnule which will soon undergo 
further segmentation; midrib in a small pinnule — generally are characterized by some 
rows of somewhat oblong cells on the lower side and by the localisation of most of the 
stomadta (pl. 2, fig. 1), which are not very numerous, to a comparatively narrow strip above 
them on the upper one. On the lower epidermis the stomata are far more numerous 
than on the upper; and here they are equally distributed over the whole surface of 
the pinnule. According to ScHENK (1867, p. 54), they should be quite missing on 
the upper side. The cutinisation is strong and similar on both sides, and the plant 
may have been succulent. The cells usually have papillae (pl. 2, fig. 4), but this is 
not always the case. 
When examining the macerated fronds, the attention is necessarily drawn to 
the strange fact that practically every segment has one or more holes (pl. 2, figs. 
2, 3, 10). These holes vary in a high degree as to their size, being in some cases 
quite small and in others rather large, and are usually rounded or a little oblong, 
but are sometimes of irregular form. They are either sharply marked against the 
uninjured part of the lamina or bordered by a very thin cutiele. In the latter case, 
one has obviously to do with a hole above which the epidermis has partly been 
regenerated, for it is by no means seldom that one sees spots where this regeneration 
has had time to become complete (pl. 2, fig. 3), and where nothing but the thinness 
of the cuticle indicates that holes once existed. The parts nearest the holes are 
generally somewhat more strongly cutinized than the rest of the epidermis, which 
is probably result of the reaction of the plant at the bursting of the cuticle. 
In explaining the formation of the holes, it is, of course, of importance to 
know whether they are limited to a certain side of the frond, or whether to fixed 
parts of it. I have already mentioned that they occur on the rachis, and an exa- 
mination of a great number of leaf-fragments has shown that they can be found on 
any part of the plant, and on either side. The majority, however, occur near the 
veins on the lower side of the segments. They are not infrequently found at the 
margins of the pinnules (pl. 2, fig. 10). 
The holes in question often remind one to no small extent of the water-pores 
in Polypodium vulgare L. But their mode of occurrence, as do other circumstances, 
argue decidedly against their having a similar function to fill or, on the whole, having 
anything direct to do with the plant as such at all. On the contrary, everything 
suggests that they are indebted to some external influence for their formation. Itis 
possible that they are caused by insects or a parasitic fungus, perhaps more prob- 
ably the latter, as that would best explain their constant occurrence. This fungus 
would have developed under the epidermis, and finally have burst it. Tf it became 
ripe long before the embedding of the plant, the resulting wound would have had time 
to heal, and new cuticle to be formed. 
The segmentation of the frond has been the subject of different interpretations 
on the part of different authors. The differences of opinion have been in reference 
