May 31, 1912] 
acteristic of all vascular plants. In this con- 
nection he definitely homologizes the moss 
sporogonium with the sporophyte of ferns. 
Obviously he entertains the view that Ophio- 
glossum among the Ophioglossacee is prob- 
ably the most primitive representative of the 
fern stock. There appears to be little support 
for the correctness of this view and it en- 
tirely lacks the confirmation of fossil evi- 
dence, which in this case is unfortunately 
lacking. Logically in accordance with the 
general attitude just indicated, the author 
derives the Marattiacee from ancestors allied 
to the Ophioglossacee. He acknowledges in 
this connection the serious difficulty of bridg- 
ing over the morphological gap, between the 
dorsisporangiate foliar organs of the Marat- 
tiales and the so-called sporangiophore of the 
Ophioglossales. This difficulty appears to the 
reviewer to be very great indeed, especially in 
view of the known antiquity of the Marat- 
tiales and the apparently recent origin of the 
Ophioglossales. It further appears from a 
consideration of the reproductive parts and 
anatomy of the sporophytes as well as of the 
gametophytes, that it is much easier to derive 
the Ophioglossacese from typical ferns such as 
the Marattiaces, than it is to entertain the 
possibility of a reverse course of evolution. 
The Morphology of Gymnosperms. By Cout- 
TER and CHAMBERLAIN. University of Chi- 
eago Press. 1911. Postpaid, $4.22. 
The present volume is undoubtedly the most 
important general work on the gymnosperms 
which has ever appeared and is highly credit- 
able to American science. It consists of four 
hundred and fifty pages and of an equal num- 
ber of, for the most part, original and remark- 
ably good illustrations. The book is charac- 
terized throughout by a sane, broad and withal 
interesting treatment. The views expressed as 
to affinities and evolutionary sequence are for 
the most part clearly, logically and con- 
vincingly stated. 
The volume is modeled on evolutionary 
lines, grounded on the solid foundation of the 
testimony afforded by the rocks, and in this 
respect presents an agreeable contrast to most 
SCIENCE 
867 
botanical works on plant evolution, which are 
too often written by persons who have no 
knowledge or appreciation of the past history 
of plants. In accordance with this feature, it 
begins with the oldest known seed-plants, the 
Cycadofilicales as the authors more logically 
term the Cyecadofilices of Potonie and the 
Pteridospermee of Oliver and Scott. The 
enormous progress made in our knowledge of 
the evolution of the gymnosperms is nowhere 
better illustrated than in this chapter, which 
may be instructively compared with the 
meager amount of information supplied on 
the same subject in the first edition published 
ten years ago. Here we find an extremely 
good aecount of this fascinating primitive 
group of gymnosperms, long mistaken for 
ferns, whose true affinities were guessed at by 
the German paleobotanist Potonie and proved 
by Oliver, Scott, Grand’Eury and David 
White. 
Logically following the Cycadofilicales, 
with the interposition of the Cordaitales, 
which need not be specially referred to in this 
connection, come the true Cycads and their 
allies the Bennettitales. The Chicago labora- 
tories have added much to our knowledge of 
the Cycadales, and the chapter on this group of 
gymnosperms, now confined to the warmer re- 
gions near the equator, is one of the strongest 
in the book. The Bennettitales, the Cycads of 
the earlier Mesozoic, owe their elucidation to 
a large extent to the striking investigations of 
Dr. Wieland, of Yale University. We find 
them treated with the fulness which their im- 
portance demands. 
Next to the Cycad-like gymnosperms come 
the relatives of the maidenhair tree, Ginkgo, 
sole survivor, through the pious care of the 
Japanese priests, of a stock which in the 
Mesozoic flourished abundantly throughout 
the northern hemisphere. 
The Conifers, the most abundant and im- 
portant gymnosperms of our existing flora 
and of great evolutionary importance on ac- 
count of their extension into the remote past, 
appropriately occupy about one third of the 
volume. The gametophytes of this group, 
which have been particularly the subject of 
