NOTICES OF NEW BOOKS. 511 
birds and Pterosaurians, particularly Pterodactyles—and Prof. 
Newton has conclusively shown most interesting resemblances— 
Mr. Beddard considers the main difficulty “‘in the way of com- 
paring Pterodacytles and birds is in the fact that both can fly, 
and that each has acquired the power of flight by a different 
method. Having acquired the power of flight, it seems clear that 
certain of the points of resemblance between them may easily be 
due to that mode of life, and may have been independently 
arrived at.” 
The consideration of the affinities brings us to the much- 
vexed question of the classification of birds, and’ ‘‘ in considering 
a scheme of classification it is clear that we must bear in mind 
indications of the descent of birds’’; and, in sketching the main 
outlines of a scheme, “‘ attention must be paid only, or chiefly, to 
those characters which birds have inherited from their reptilian 
ancestors.” But here a difficulty arises, if we seek the plane of 
low level in organization, by a plethora of undoubtedly reptilian 
characters. For ‘the few specially reptilian features in the 
organization of birds have, so to speak, been distributed with 
such exceeding fairness through the class that no type has any 
great advantage over its fellows.” ~ 
Such discussions and conclusions as the above show the 
philosophical questions which may be debated and considered 
by the anatomical details of this volume, with its wealth of 
illustration. It would no doubt be possible to criticize; fault- 
finding is a facile occupation, but to recognize the great merits 
of a book is a more instructive process, even for a reviewer, 
than the eager quest for an error. We hold with Prof. Nichol 
on a literary subject—and the same remark applies to science— 
some “‘criticism has for its aim to show off the critic; good 
criticism interprets the author.” This book is a standard con- 
tribution to ornithology. 
Text-Book of Zoology. By H. 8. Wetus, B.Sc. Lond., &c., 
and A. M. Davies, B.Sc. Lond. London: W. B. Clive, 
University Correspondence College Press. 
Tus is a new edition, “almost completely” rewritten, of 
Wells’s ‘ Text-Book of Biology,’ published some five years back. 
