Recently published Ornithological Works. 179 
furnish much food for thought; while the pugnacity and 
display of the males are considered in connexion with their 
ways in the breeding-season. Mr. Pycraft devotes a good 
deal of space to the question of reproduction and care of the 
young, and impresses upon us the fact that the study of 
Birds is one of living organisms, moulded by their inherent 
constitution and by the struggle for existence ; while his 
whole book shews how far evolution has succeeded in attaining 
the objects for which it was intended. His knowledge of 
Osteology and Pterylography has greatly assisted him 
throughout, and he has taken much trouble to collect the 
large mass of facts which he now produces for our edification. 
Embryology is not treated in great detail, as it constitutes 
a separate subject in itself, but the young bird in general, its 
coloration, its changes of plumage up to the. adult stage, and 
so forth, are discussed at considerable length. The author 
is inclined to minimize the effect of sexual selection and to 
rely on natural selection as the chief agent in the production 
of a robust progeny, while he does not consider that acquired 
characters are transmissible. Apart from the special interest 
of the evolutionary development of the bird-world, there is 
much worthy of note in the final chapters, which among 
other subjects deal with artificial selection, the effects of 
isolation, structural and functional adaptations ; while the 
last chapter of all is devoted to an account of convergent 
evolution, as in the case of the Owls and the Nightjars. 
Mr. Pycraft states his own views freely throughout, and in 
most places we cordially agree with him, but in some cases* 
such as his theory of a direct north and south migration, we 
are hardly disposed to follow him on present information. 
In conclusion, we must not omit to mention Sir Kay 
LankestePs masterly preface, which not only sums up 
admirably the main points of the book, but serves to call 
attention to those that are to be considered of the greatest 
importance. 
This f History of Birds 3 is one of the volumes of a series 
on f Animal Life/ produced under the editorship of Mr. 
Pycraft, and we have no doubt that the whole of them will 
