NOTICES OF NEW BOOKS. 157 
seem to be the only authors who have given them the benefit of 
a practical application. In their ‘Nomenclator Avium Neo- 
tropicalium’ a modification of the new classification is adopted, 
which Mr. Sclater has done much to popularise in each successive 
edition of the ‘List of Vertebrates now or lately living in the 
Gardens of the Zoological Society of London.’ But it is to be 
noticed that the new nomenclature proposed by Prof. Huxley is, 
by all his followers, rejected. It is found more convenient in 
practice to use the name Passeres than, out of simple regard for 
uniformity, Coracomorphe ; the name: Columbe has a familiar 
ring that its Huxleyan equivalent Peristeromorphe can never 
reach; and the credit of giving popular currency and scientific 
limitation to old names is due, not to Prof. Huxley, but to 
Mr. Sclater. One obvious advantage of the new method is that, 
in place of the old six or seven unwieldy “orders” of European 
birds, we have, in Mr. Dresser’s List, no less than sixteen orders, 
and the familiar names go far to simplify the comprehension of 
the new system. Anatomists seem pretty well agreed that Prof. 
Huxley’s classification of birds is the best that has yet been 
proposed, but ornithologists who follow him ought, in common 
fairness, to be careful to acknowledge that it is his principles 
rather than his practice that they adopt. 
Now Prof. Huxley subdivides all species of birds that exist at 
the present day into (1) those that have a keeled sternum, which 
gives attachment to the muscles that act upon the wings, and 
(2) those that have no keel developed on the sternum at all ; 
the one group he calls Carinate (from carina, a keel), the other 
Ratite (from ratis, a raft). This he does on the principles of 
the theory of Evolution, taking for granted that all birds had a 
common ancestor; that some groups had no necessity for the use 
of wings, therefore muscles to move them became, in course of 
time, an impediment rather than an assistance; while others 
_ could only support existence by emphasising the faculty of flight. 
In Europe we are only concerned with the Carinate. These 
Prof. Huxley divides according to peculiarities in the construction 
of their skulls; and he takes such a point because it can only be 
in the most remote degree referable to the individual bird’s 
manner of life; it is not a character which can ever have had its 
origin in external circumstances; it must have arisen from 
genetic divergences. He finds that one group of birds has the 
