May 14, 1914] 
descriptive sections comprise only just such con- 
spicuous families and genera as are needed by a 
student who seeks a broad view of the subject; 
and at the end of the chapter on each class there 
is a brief summary of the leading features in tie 
geological distribution and evolution of the class 
as a whole, with a table of diagnoses of its larger 
subdivisions. A useful list of the principal papers 
and books published during the last few years is | 
also appended. The text throughout is well illus- 
trated with drawings of more than usual artistic 
merit, and although the majority of them are 
taken, with acknowledgment, from _ various 
original works, Dr. Stromer himself has fre- 
quently amended them to bring them up-to-date. 
Some, indeed, are in advance of their formal 
publication, such as the drawing of the skeleton 
of the strange clawed ungulate mammal Moropus, 
contributed by Dr. W. J. Holland. 
new to a text-book that their appearance is quite 
refreshing. 
In a work designed for elementary teaching it 
is generally advisable to incline towards conserva- 
tism, and Dr. Stromer evidently holds this opinion. 
Among fishes, for instance, he still recognises 
the “orders”? Ganoidei and Teleostei, though his 
so-called diagnoses do not define them; and his 
treatment of the early paleozoic Arthrodira and 
Ostracodermi is not altogether satisfactory from 
the modern point of view. His references to the 
literature, however, will enable the student to 
examine other views if he wishes to do so. 
The last sixty pages of the book are devoted 
to the general principles of paleontology, and we 
can recommend this able summary to any zoologist 
who desires to understand the present position of 
those who study fossils. ALS. W. 
A Treatise on Wooden Trestle Bridges and their 
Concrete Substitutes. By Wolcott C. Foster. 
Fourth revised and enlarged edition. Pp. xix + 
440. (New York: John Wiley and Sons, Inc. ; 
London: Chapman and Hall, Ltd., 1913.) 
Price 215s. -net. 
In the present edition of this work, which was 
first published in 1891, will be found a very full 
account of the construction, erection, maintenance, 
and preservation of timber trestle bridges. The 
book is profusely illustrated, and contains work- 
ing drawings showing the details of the standard 
trestles used on the principal American railroads. 
Wooden trestles may be disappearing gradually 
from main lines of heavy traffic, but the increased 
growth of branch lines, or feeders, and of trestles 
at manufacturing plants and for electric railways, 
have probably more than kept pace with its aban- 
donment on main lines. There is, on the average, 
about too ft. of bridges and trestles to each mile 
of railroad in the United States. The wearing out 
of wooden trestles and the increasing cost and 
scarcity of timber suitable for their replacement 
has taxed the ingenuity of railroad officials to find 
suitable structures to take their place. In some 
cases iron or steel structures have been employed, 
but there are numerous districts where local con- 
NO. 2324, VOL. 93| 
So many are | 
NATURE 
IMenSs 
267 
ditions make these methods so expensive as to be 
prohibitive. 
In the past few years a number of roads have 
used concrete trestles iin replacing those con- 
structed of timber, and the author gives full par- 
ticulars of reinforced concrete trestles and slabs 
which form a structure closely in line with the 
main features of the timber trestle. The book pro- 
vides a great deal of valuable information regard- 
ing the strength, durability, and preservation of 
| timber under all kinds of practical conditions, and 
therefore will be of service to British engineers, 
despite the fact that timber bridges do not occur 
often on British railways. 
Durch Kénig Tschulalongkorns Reich. Eine 
deutsche Siam-Expedition. By Dr. Carl C. 
Hosseus. Pp. xii+219+plates. (Stuttgart: 
Stecker and Schroder, n.d.) Price 15 marks. 
Dr. C. C. HosseEus, who visited Siam in 1904-06, 
gives us in the present volume an account of his 
journey and scientific observations. The route lay 
up the Maping, and at various halting-places ex- 
cursions were made to the neighbouring country. 
Chiengmai appears to have been his chief base, 
and from there Doi Intanon, Chieng Dao, Pahom- 
buk, and Chiengrai, to mention only a few of the 
more important, were visited. 
Zoologists, geologists, ethnologists, geograph- 
and other naturalists will all find much to 
interest them in the book; for quite a casual glance 
through its pages will suffice to show that the 
author was ever on the alert to note points of 
interest in any branch of science. But it is un- 
doubtedly to the botanist that the author has in 
the first place appealed. 
Previous to this work the author had published 
lists of his botanical collections, so that here we 
have no complete catalogue, but references are 
given to the new species found and to many others 
interesting for some morphological detail or for 
their associations. Here it may be noted that the 
index, copious though it may appear, is not a 
complete index to afl the plants mentioned. 
A word of praise is due for the numerous ex- 
cellent illustrations included at the end of the 
book. All who are interested in Asiatic botany 
must feel indebted to Dr. Hosseus, to whom must 
be attributed the credit of being the first scientific 
traveller and collector on a large scale north of 
Bangkok, for supplementing his previous lists 
with such an interesting book. 
Biology: General and Medical. By Prof. Joseph 
McFarland. Pp. 457, with 160 illustrations. 
Second edition. (Philadelphia and London: 
W. B. Saunders Co., 1913.) Price 7s. 6d. net. 
Tue first edition of Prof. McFarland’s book ap- 
peared in 1910, and was reviewed at length in the 
issue of Nature for March 23, 1911 (vol. Ixxxvi., 
p. 106). In the present edition the author has en- 
deavoured to eliminate defects discovered in the 
book, and without much increasing its size to 
introduce the new matter necessary to bring it 
up to date. 
