1 91 8.] Recently published Ornithological Works. 503 



hypothetical and problematically of little value. The writer, 

 however, accepts that some species of Petrels are more or less 

 sedentary, and the problems of Petrel migration must be 

 considered in conjunction with geographical races. Loomis, 

 however, concludes " Bird species are realities,''^ and " In 

 the present paper geographic variation is considered in 

 conaection with the other variations of species, the sub- 

 species theory being discarded as a theory that has outlived 

 its usefulness/^ As a matter of fact, geographic variation 

 is not dealt with at all, probably the real reason being lack 

 of specimens — a very potent factor. The Academy Collection 

 is said to number over two thousand, and at the time of 

 writing constituted the largest collection of these birds in the 

 United States. As, however, about nineteen hundred skins 

 are recorded for sixteen species from the Galapagos and 

 adjoining seas, the poverty of such a collection may be more 

 correctly estimated by the admission that about a hundred 

 species have been described and there were about a hundred 

 or so skins to consider their validity by. Consequently the 

 fourth part, dealing with Variation, is more or less the result 

 of study of this feature in this one localit3^ The results must 

 be contrasted with those secured elsewhere, before any con- 

 clusions can be fairly provided. A majority of moulting birds 

 appear to have been studied, and conclusions based on these 

 without consideration as to their breeding-place. Further, 

 these were often killed in the breeding-season, though many 

 thousands of miles distant from any known breeding-place 

 of their species ; and this points to their aberrant nature, 

 probably being non-breeding birds of the year or physically 

 unfit. Dichromatism is given a big place throughout, any 

 unrecognized variation being put down to this cause. 



The fifth part, dealing with Classification and Nomen- 

 clature, certainly shows novel features, which in other cases 

 might be attributed to atavism : thus, '^ I heartily agree with 

 Dr. Keichenow that the genealogy of birds is a sul)jeet to 

 be considered apart from their classification/^ The novelty 

 cannot be recommended when such results as the lumping 

 of Diomedea exulans with ckionoptera and regia are the 



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