1910] CURRENT LITERATURE 61 
the Botryopterideae as sure representatives of paleozoic Filicales. It must 
always be remembered, however, that all the members of the great frond genera 
have not been proved to be seed plants, but they are all under suspicion. 
Of course the “‘pteridosperms” are presented with a completeness that has 
not been possible heretofore. In traversing the evidence, Scorr reaches the con- 
clusion that every great frond genus is involved in the seed-bearing habit, and 
also in the discovery of stamens. It is of interest to note that the Crossotheca 
(“epaulet”) type of stamens is probably the prevailing kind, and that the so-called 
Calymmatotheca (“‘cupule”’) type is likely to be the husk or cupule of seeds. 
he statement that Gnetopsis elliptica, which has been one of the guesses at a 
history for the Gnetales, is probably a seed of the Lyginodendreae relieves a very 
doubtful situation. 
The perspective of the Cordaitales is increased by the recognition of Poroxylon 
and Pitys as intermediate in vascular structure between Lyginodendron and 
Cordaites, the gradation from the mesarch cylinder of the former to the endarch 
cylinder of the latter being very complete. As a consequence, the group Cor- 
daitales is made to comprise Pityeae, Poroxlyeae, and Cordaiteae. 
The mesozoic Bennettitales represent the second great vascular group that 
has been brought to light during the last decade, and their presentation is another 
new feature of the volume. WreLAND’s laborious researches have developed 
a knowledge of this extinct and widely distributed cycadean group that almost 
rivals that of the living groups. Scott inclines to follow W1rLAND’s suggestion 
that the remarkable strobilus of Bennettitales must be taken into consideration 
in searching for the origin of the angiosperms, a view that is certainly not contra- 
dicted at present by the history of the two groups. - 
Pethaps the most significant suggestion in the volume is a proposed new 
classification of vascular plants. Scorr evidently feels that the old division into 
Pteridophytes and spermatophytes has about outlived its usefulness, a feeling 
doubtless shared by all morphologists who deal specially with the two groups. 
hether the exact form of the suggestion will be acceptable or not remains to be 
Seen, but the author is to be congratulated upon being bold enough to break the 
Silence again. His suggestion is that vascular plants be grouped in three primary 
assemblages: Sphenopsida (Equisetales, Pseudoborniales, Sphenophyllales, 
Psilotales), Lycopsida (Lycopodiales), and Pteropsida (Filicales, Pteridospermeae, 
Gymnospermeae, and Angiospermeae). This crosses the old division, and the 
author expresses the opinion that “the traditional classification will no doubt 
Continue to be used on grounds of convenience;” in fact, the two volumes, in 
which the present work also appears, bear the subtitles “Pteridophyta” and 
‘Spermophyta.” Pteropsida and Lycopsida are names proposed by JEFFREY, 
Who made a similar proposition years ago. The former name is used as JEFFREY 
defined it; but the latter is limited to the Lycopodiales, as the only “typically 
microphyllous phylum.” Scort does not think that the “‘sporangiophoric pterido- 
Phytes” (Bower’s name for Scort’s Sphenopsida) show an affinity for the 
lycopods that would justify their inclusion under a common name.—J. M. C. 
