on Mr. G. R. Gray's ' Genera of Birds. 9 411 



bers. Few persons would imagine, without seeing Mr. Gray's 

 book, the enormous extent to which this evil has grown, 

 loading the science for ever with a mass of utterly useless 

 synonyms, and compelling the unwilling naturalist too often 

 to desert the works of Nature in order to disentangle the er- 

 rors of man. Much of this multiplication of synonyms is, 

 indeed, the unavoidable result of the number of labourers 

 employed in the same branch of science, but separated by 

 wide geographic intervals. The machinery for circulating 

 through the civilized world the knowledge which is daily 

 published in detached regions is so imperfect, that it is next 

 to impossible for any individual to gain access to all the works 

 which relate to his particular study. Mr. Gray's office in the 

 British Museum has given him great advantages in this re- 

 spect, and he has availed himself of them to good purpose. 

 His work appears to me highly creditable to him as a first 

 attempt at bringing into order the heterogeneous materials 

 which lay before him. His book is, indeed, by no means free 

 from defects and inaccuracies, but they are few in compari- 

 son with the errors which he has detected in the writings of 

 others. It would not have been possible for any man living 

 to render such a work accurate at first. One person will al- 

 ways discover mistakes where another does not, and the 

 greater the number of critics the more accurate the book may 

 ultimately become. Having myself been engaged for a con- 

 siderable time in preparing a work on the synonyms, specific 

 as well as generic of the class Aves, I have been enabled by 

 comparing Mr. Gray's work with my own MSS. to judge of 

 his general accuracy. In most cases his results have entirely 

 agreed with my own, and where they differed I have been led 

 by further investigation to detect errors, sometimes in my 

 work, and sometimes in his. It appeared desirable to em- 

 body these corrections in a detailed commentary on Mr. 

 Gray's book, both for the information of those who possess 

 it, and also to aid Mr. Gray in case he should publish a second 

 edition. A corrected edition of the c Genera of Birds/ if widely 

 circulated on the Continent as well as at home, would be 

 the most effectual means of introducing an uniform nomen- 

 clature into ornithology, of stopping the present wanton and 

 lawless multiplication of synonyms, and of opening the eyes 

 of naturalists to the amount of labour which has already been 

 effected in the same department by others. 



The remarks contained in Mr. Gray's preface are very ju- 

 dicious, and deserve to be read and acted upon by all zoolo- 

 gical authors. In selecting and forming a permanent nomen- 

 clature out of a heap of synonymous terms, Mr. Gray adopts 



