356 BOTANICAL GAZETTE [MAY 
morphology of the ovuliferous scale of the Coniferales they occupy a judicial 
attitude, although obviously inclining to the view that in the Pinaceae at any 
rate it is to be regarded as a modified shoot in the axil of the sterile bract. 
Concerning the treatment of the Gnetales little need be said. Although of 
necessity presenting no original features it summarizes the most recent litera- 
ture. 
In its treatment of the fossil Gymosperms the present work is far beyond 
any previous American botanical work. The Cordaitales receive a sufficient 
consideration, illustrated chiefly by Renault’s well-known figures. The 
extinct cycadoid group, the Bennettitales, is fully discussed from the stand- 
point of the existing literature, and an interesting account, in part original, is 
given of the recently discovered microsporophylls of the group, which as yet 
have been found in a state of suitable preservation only in the United States. 
The microsporangia occur in synangial sori on the abaxial surfaces of the 
sporophylls, thus resembling at once Cycas and the marattiaceous ferns. A 
further interesting feature is that the strobili in this group were not unfre- 
quently bisporangiate, bearing both megasporophylls and microsporophylls. 
The work closes with chapters on the comparative morphology, phy- 
logeny, and geographical distribution of the Gymnosperms. As regards 
comparative morphology the authors have almost entirely excluded vegetative 
anatomy from their work, and among so many admirable illustrations of the 
external features and reproductive organs of living and fossil Gymnosperms 
there are few or none representing anatomical structures of the vegetative 
organs. The present volume is destined to have such an important influence 
on the study of Gymnosperms on our continent, that it is impossible not 
to regret that its authors have not done something to direct the attention of 
American botanists to the importance of anatomical studies, so much neg- 
lected as yet in North America. The work of European palaeobotanists has 
apparently finally set at rest the claim that the reproductive organs of the 
higher plants are the only trustworthy guide in matters of morphology and 
phylogeny. It appears to be established as a result of the work of the late 
Professor Williamson and his followers that the fibrovascular skeleton of 
plants is quite as important phylogenetically as the osseous skeleton has 
er to be in the case of animals. The Calamities and Sigillariae, for 
example, were put by Williamson, on account of the constant and character- 
istic features of structure of their vegetative organs, with the Equisetales 
and Lycopodiales respectively, in opposition to Brongniart who placed them 
among the Gymnosperms. The subsequent discovery of their reproductive 
organs by Williamson and Zeiller only confirmed Williamson's predictions. 
At the present time the Cycadofilices, a group on anatomical grounds alone 
considered transitional between the Filicales and Gymnosperms, are in the 
same position as that formerly occupied by the Calamites and Sigillariae. 

