468 Recent Literature. ' LOct. 



species and the elimination of a considerable number of others since the 

 publication of the first edition twenty-four years ago. 



The first edition of the American Ornithologists' Union Check-List of 

 North American birds (1886) contained 768 species, serially numbered, 

 and 183 subspecies, indicated by the letters a, b, c, etc., placed after the 

 species number, which was repeated for each subspecies. The number of 

 forms recognized was 951. Of this number 82 species were indicated (by 

 the species number being inclosed in brackets) as of merely casual or 

 accidental occurrence, leaving only 869 forms that were to be regarded as 

 properly North American birds. 



The second edition (1895), published nine years after the first, con- 

 tained 799 species and 269 subspecies, making a total of 1,068 forms, a 

 net gain of 31 species and 86 subspecies, or 117 forms. 



The third edition (August, 1910), appearing fifteen years after the 

 second, contains 802 species and 394 subspecies — a total of 1,196 forms 

 (1,200 in round numbers). This is a net gain over the second edition of 

 3 species and 125 subspecies. 



A comparison of the third edition with the first shows that in the twenty- 

 four year interval the net gain has been 34 species and 211 subspecies. 

 Many more than these numbers have been added, but a large number of 

 species and subspecies have also been eliminated. Thus in the second 

 edition, while 38 species and 83 subspecies were added, 7 species and 3 

 subspecies included in the first edition were either eliminated or changed 

 in status. In the third edition, there were numerous changes of a similar 

 character. 



It is difficult to summarize all of the varied and numerous changes in 

 respect to species and subspecies that have been made in the gradual 

 evolution of the Check-List from the first edition to the third. An approx- 

 imate analysis is attempted in the following table, with a deep conscious- 

 ness of the liability of there being in it a small percentage of error. 



First Edition. 



Number of species 768 



" " subspecies 183 



Total number of forms 951 



Second Edition. 



Number of species 799 



" " subspecies 269 



Total number of forms 1068 



Species omitted 7 



" added 38 



" net increase 31 



Subspecies added 90 



" omitted 4 



" net increase 86 



