284 
EEVIEWS. 
PROFESSOR HUXLEY ON CLASSIFICATION.* 
I N the year 1864 Professor Huxley brought out a volume on Comparative 
Anatomy^ which he then said he hoped to make the first of a series. It 
included the subjects of Classification and the Construction of the Skull. 
This work, owing to the author’s time having been absorbed by original 
investigations, has not been followed up, and naturalists cannot but regret 
the circumstance. The first part, however, of the volume contained matter 
which was of importance not only to the professional comparative anatomist, 
but to the student of general natural history, since it laid down Professor 
Huxley’s views as to the principles and scheme of animal classification. 
The book very soon got out of print, and Professor Huxley thought it advis- 
able to re-issue with some additions the poidion of it which was devoted to 
classification. The volume now before us is the consequence, and we think 
that all Zoology students will thank the author for reproducing it in its 
present form. 
We need not tell those who know anything of Professor Huxley’s writings 
that this book is condensed without losing either force or interest, and that 
it has been prepared with the utmost care and contains nothing in the shape 
of dogmatism. In stating his opinions as to the systematic arrangement of 
animals, the author shows a preference for the division into classes, which he 
considers to be better defined than any of the other zoological landmarks. 
Instead, therefore, of definitively grouping animals under four or five dis- 
tinct sub-kingdoms, he treats of classes from the lowest to the highest. The 
reader must not expect to find that Professor Huxley has removed all the 
stumbling-blocks from his way. There are groups of animals whose cha- 
racters and development are as yet so insufficiently known that it is impos- 
sible to determine their affinities satisfactorily. These the author does not 
place definitively under any division. He may rank them provisionally in a 
certain position, but he very decidedly declares his doubts, when he has any, 
aa to the ultimate justification of this particular mode of an’angement. The 
group Scolecida illustrates this fully. Under this title the author places 
the wheel-animalcules, the Flukes, Tape- worms. Thread-worms, Turbellaria, 
Gordiacea, and Acanthocephala. But contrasting this class with that of 
the sca-urchins, he says : “Nothing can be more definite, it appears to me, 
than the class Echinodermata, the leading characteristics of which have 
• “An Introduction to the Classification of Animals.” By Thomas 
Henry Huxley, LL.D., F.R.S. London : Churchill, 1869. 
