REVEW5 



A History of Birds. By W. P. Pycraft. Illustrated. (Methuen 

 & Co.) 10s. 6d. net. 



Mr. Pycraft has produced an extremely interesting book, 

 and, besides this, one which throws new light on some 

 important questions. The plan which he has followed is 

 one which, unfortunately, has up till now but rarely com- 

 mended itself to writers of books on natural history. He 

 does not merely describe structure and habit, and call upon 

 us to wonder at what is curious, but he asks perpetually 

 Whence ? and Why ? And this gives to the book an excep- 

 tional interest. To Mr. Pycraft the bird is a metamorphosed 

 reptile. The acquisition of the power of flight has dominated 

 everything, so that variations have been confined within 

 narrower limits than is the case with mammals. The 

 necessity of flight has allowed none to deviate very far, 

 though some few species, after aspiring to the realms of air, 

 have lapsed to earth again. Hence the great difficulty of 

 the classification of birds : the number of forms is vast 

 and the differences by the light of which they can be divided 

 and subdivided are small. However, the subject of classifica- 

 tion is well and clearly dealt with by Mr. Pycraft, and when 

 his account of it is read in connection with a later chapter 

 on convergent evolution, the interest becomes very great. 

 When the comparatively conservative muscles and viscera 

 are examined rather than the comparatively plastic bony 

 framework, new relationships come to light : the Owls, for 

 example, have to be severed from the Hawks and become the 

 kin of the Nightjars. 



Mr. Pycraft writes of geographical distribution, the effect 

 of moisture and temperature, migration, the relation of birds 

 to the animate environment (they pollinate flowers, they 

 distribute seeds), peculiar inter-relations {e.g., between Bee- 

 eaters and Bustards), gregarious habits, nidification, care of 

 offspring, phases of plumage (a subject in which he has made 

 original investigations), natural selection (its methods of 

 working are well described), sexual selection, isolation, adapta- 

 tion. Since these are only some of the subjects treated of, 



