JUNE 28, 1912] 
repetition. But the fault seems to be due also 
to a fear that the reader will have forgotten 
or overlooked or misunderstood the signifi- 
cance of something the author considers of 
great importance. This desire to be perfectly 
understood leads to an exceptionally large 
number of references to plates and figures and 
to other passages in the text, so that the read- 
ing tends to become slow and laborious, or if 
the references be ignored, it tends to be super- 
ficial. In the explanation of the plates, the 
author’s care for details is shown to a marked 
degree. It is safe to say one rarely sees a vol- 
ume in which the explanatory text for the 
plates is so complete. So far as the state- 
ments or interpretations of facts are con- 
cerned, the author’s freedom from obvious 
error and from ill-judged conclusions is really 
remarkable. In all his references to other 
workers, Jackson shows not only an open- 
mindedness and fairness of judgment, but a 
courtesy even in disagreement that is delight- 
ful. At the same time, there is no glossing 
over of mistakes in earlier publications, no 
matter whether made by himself or some 
other authority. The perfectly evident desire 
to know the facts as they really are wins the 
reader’s confidence and the unusual freedom 
from ambiguity prevents any misunderstand- 
ings. 
The typographical work reflects the great- 
est credit on the Cosmos Press, especially when 
one considers the numerous tables with per- 
centages often worked out to two decimals 
and the abundance of scientific names and 
technical terms. That slips of the pen and oc- 
easional transposed letters should occur is 
inevitable; the extraordinary thing is how very 
few there are in this volume. Nearly all have 
been detected and gathered together on the 
page of “Errata and Addenda” which fol- 
lows the index, but they are mostly so trivial 
as to be of absolutely no importance. On 
page 188, however, the phrase “ distinct con- 
tinuous base ” carries no meaning and we are 
therefore glad to have the Errata explain that 
it should read “discontinuous base.” On 
page 251, we are told by the Errata, the words 
“ starfish ” and “sea-urchin ” have been trans- 
SCIENCE 
993 
posed in the author’s discussion of Paleodis- 
cus, an error which if uncorrected would 
seriously affect the argument. Two slips not 
noted in the “ Errata,” although not of great 
importance, may perhaps be worth pointing 
out. On page 121, in the footnote it is said 
that Toxopneustes atlanticus was described by 
Mr. Agassiz as Leptechinus atlanticus; the 
generic name should read Lytechinus. On 
page 238, the order Bothriocidaroida is inad- 
vertently attributed to Jackson, 1896, whereas 
Dunean introduced the term in 1889. 
When Alexander Agassiz’s “ Revision of 
the Echini” was published in 1872-74, it 
marked an epoch in the study of sea-urchins. 
Tt has literally been the foundation of all sub- 
sequent work throughout the world. It 
brought together and summarized the knowl- 
edge of echini as it stood at that time and 
much of the work it involved need never be 
done again. Jackson’s “Phylogeny of the 
Eechini” is a similar summing up of our 
knowledge to-day from the twentieth-century 
point of view and, like the “ Revision,” it 
marks an epoch. We are all to be congratu- 
lated that this fitting companion volume to 
the “ Revision ” is the work of an American 
zoologist; the Boston Society of Natural His- 
tory 1s to be congratulated on the publication 
of a memoir of such unusual merit; and Dr. 
Jackson himself is most of all to be felici- 
tated on the production of such a profound 
and masterly piece of research. 
Hupert Lyman Criark 
The Parasitic Amebe of Man. By CHARLES 
F. Crate, M.D., Captain, Medical Corps, 
U. S. Army. 1911. J. B. Lippincott Com- 
pany. Pp. 258. $2.50. 
This book has no doubt been welcomed by 
many medical men, for it brings together the 
seattered literature in a complex field. In 
making such a compilation it is natural, per- 
haps, that the author should be biased by his 
own investigations. However, it is unfor- 
tunate that this fixed attitude should be so 
much in evidence throughout a work the pur- 
pose of which is to aid medical men in their 
studies of amcebic infections. A more critical 
