Review of Recent Geological Literature. 197 
The second volume of the work, in which we are promised a dis- 
cussion of the question of the formation of coal, should be much larger 
than the first, if the treatment of the classes in the Lycopods, Gym 
nosperms, and Angiosperms is proportionate to that of the Alg:e and 
Calamarise in the first volume. It should be remarked that the sec- 
tions on these two groups of fossil plants are especially valuable and 
interesting. The first is conservative, critical, yet thorough and dis- 
creet. The presentation of the second group, in which Seward fol- 
lows the British and German paleontologists by including Calamopitys 
and Arthropitys, is well balanced, complete and very instruc.ive. The 
work shows a wide range of learning, and thorough conversance with 
the particular subject. The method of treatment is original, the style 
is clear and concise, and the illustrations are excellent as well as pro- 
fuse, a large number being new. 
As indicated above. Dr. Seward's work is not only abreast of paleo- 
botanical progress up to date, but it is probably the best popular manual 
on the subject in existence. Considering the dual character of his 
audience it is probably as successful a work as lies in the power oi 
any one living man. The author of this review does not. however, 
regard it as most practicable to write to both geologists and botanists 
in the same manual. Too great an amount of energy and time are 
necessarily consumed in botanical elementaries for the geologist, and 
in geological fundamentals for the botanist. Of course they are need- 
ful; indeed they are most beneficial, but each to its class. In the 
writer's opinion the need of the general geologist and stratigrapher is 
for a work which shall present in comprehensive view the sequence of 
plant life on the globe with special reference to the generic composition 
(briefly systematized) of the floras of each period, and particularly 
for profusely illustrated groups to show the species characteristic oi 
each period, stage, or formation, so refined as may be practicable, from 
the Cambrian onwards, accompanied by a brief statement of some 
of the distinctive characters of the species and their vertical range, 
with appropriate phylogenetic references to" recent types which the 
reader may then consult in proper botanical repositories. Nothing, on 
the other hand, can be of more value to botany at' the present day-when 
so many botanists have turned to phylogenetic speculation and are 
groping, often in ignorance of paleobotanical discoveries, in search 
of lines of descent and a more natural system of plant classification — 
than to impart to students of living plants some proper conception of 
the value of geologic time, and the proportions of the eras and periods 
during which certain types existed while bringing to their attention 
what is known as to the floras of the successive periods, the first ap- 
pearance of types and iheir sequence, with all available histological 
•data and, if you will, speculation, from the palemitological standpoint 
•as to their genetic relations. i>. w. 
