1912] CURRENT LITERATURE 71 
on the problems engaging the plant physiologist and morphologist. Mention 
should also be made of the wealth of excellent illustrations accompanying the 
text.—W. MARQUETTE. 
The Eusporangiatae 
CAMPBELL has published? a summary of the present knowledge concerning 
the morphology of the Ophioglossaceae and the Marattiaceae. His own 
studies of these forms have extended through twenty years, and his oppor- 
tunities for observing and collecting tropical material have been unusual, so 
that such a summary is extremely valuable in bringing together the author’s 
results and conclusions. _ The chief interest connected with this assemblage of 
plants is that in all probability it represents in the present flora the very 
ancient group which gave rise to seed plants. The main thesis of the work, 
however, is that Ophioglossiceae and Marattiaceae are genetically related, 
and that species of Ophioglossum are to be regarded as the most primitive forms 
of this assemblage, and in fact the most primitive living vascular plants. 
There is hardly room for difference of opinion today as to the close relation- 
ship that exists between the Ophioglossaceae and the Marattiaceae, and it is 
” time to remove the Ophioglossaceae from their isolation as Ophioglossales, and 
to associate them with Marattiaceae as eusporangiate Filicales. As to the 
extremely primitive character of Ophioglossum and its relatively direct con- 
nection with the bryophytes, there is room for considerable difference of 
opinion. 
The connection of Ophioglossum with bryophytes of the Anthoceros type is 
presented fully and skilfully. In embryogeny, the Eusporangiatae are charac- 
terized by the late development of the vegetative organs, as contrasted with 
the leptosporangiates, so that the young sporophyte is much more fully devel- 
oped before it becomes independent of the gametophyte. In oe several 
roots and leaves may be developed before independence, and in some cases 
even spores are formed before the two generations become completely oene 
Moreover, the young sporophytes of Ophioglossum and Anthoceros resemble 
one another in appearance, with the massive foot in both cases, and the spore 
case of the latter represented by the cotyledon of the former. The author 
sees in this cotyledon, now sterile, a “ pro-Ophioglossum” with a sporangiferous 
cotyledon, and with a stemless body, consisting of only leaf and root, the latter 
feature still being true of O. moluccanum. Of course the so-called “imbedded” 
sex organs of Anthoceros have long been recognized as a pteridophyte feature. 
The sperms of Anthoceros and Ophioglossum are regarded as perhaps the greatest 
obstacle, but if pteridophytes have been derived from bryophytes, that obstacle 
was overcome somewhere, either outside of the group or-within i 
In oe to the subterranean gametophyte, which elintacterizes both 
Ca AMPBELL, D. H., The Eusporangiatae, the comparative morphology of the 
Ophioglossaceae and A icheeticbea Carnegie Institution of oo Publ. 
no. 140. pp. vi+229. pls.-13. figs. 192. 1911. 
