Review. 
277 
REVIEW 
“ Fossil Plants. A Text Book for Students of Botany and 
Geology.” By A. C. Seward. Vol. IV, Cambridge, 1919, pp. XVI and 
543, Figs. 630—818. 
T HE fourth and last volume of Professor Seward’s text book 
of palaeobotany completes the account of the fossil 
Gymnosperms, including the Ginkgoales, Coniferales and 
Gnetales. The Ginkgoales, which formed a considerable element 
of many past floras, are fully treated, but they are known mainly 
by leaf impressions, the abundance of which makes it surprising 
that so little is known of other parts of the plant. There are 
scarcely even any reliable records of fossil Ginkgoalian wood. A 
short chapter at the end of the book is sufficient for supposed 
fossil examples of the Gnetales, none being of any great botanical 
importance, and the main part of the book is devoted to the 
Coniferales, introduced by a very valuable and well-illustrated 
chapter on recent conifers. 
In dealing with fossil forms, the foliage shoots and reproductive 
organs, though often difficult to correlate, are described together 
by Professor Seward as far as possible under each family, with an 
additional chapter for wholly doubtful genera, while the wood is 
given separate treatment. This arrangement is undoubtedly the 
best in the present state of palaeobotanical knowledge, which makes 
it very difficult to get a connected idea of the plant as a whole, a 
difficulty which is reflected in the nomenclature used by 
palasobotanists, necessitating the use of provisional “ generic 
rubbish-heaps” such as Brachyphyllum and Pagiophyllum , and the 
multiplication of “genera” for different organs of what may be 
the same plant. The use of the same name for sterile branches 
and for unconnected cones has in the past added considerably to 
the confusion, and the present exhaustive work has reduced to 
something like order the terminological chaos which enveloped the 
numerous fossil impressions of twigs, leaves and cones, and will 
considerably lighten the task of all future workers. 
The classification of fossil coniferous woods as revised by 
Gothan is accepted with some modifications by Professor Seward, 
who thinks that Gothan has carried generic subdivision too far. 
For example, he substitutes a new name, Mesembrioxylon , for the 
two genera Podocarpoxylon and Phyllocladoxylon. These two 
groups are certainly very difficult to distinguish, even when the 
preservation is perfect, and it is perhaps best for the present not 
to attempt to separate them, but Professor Seward’s view of the 
implications of the names would probably not be admitted by Dr. 
Gothan. Speaking of Podocarpoxylon and Phyllocladoxylon (p. 203) 
he says “ the use of Gothan’s names implies affinities to recent 
genera which there are no adequate reasons for assuming,” yet on 
another occasion he himself states that “ the fossil wood described 
under Cedroxylon does not denote that the parent plants were more 
closely allied to Cedrus than to some other genera of the same 
family” (p. 369), which seems to be the most satisfactory view to 
take of all such names. And if fossil woods have been too 
