Letters^ Announcements, S^c. 361 



are far less closely united together than those which make up 

 the division of the Schizoc/nathce. 



All classification by logical categories, such as that which I 

 have attempted in birds, however, is more or less artificial, and 

 must be regarded as simply a first and most important stage in 

 the progress towards the ultimate goal, which is a genetic 

 classification, — a classification, that is, which shall express the 

 manner in which living beings have been evolved one from the 

 other. 



Classification by gradation, and the formation of natural series, 

 is another stage in the same progress, and must by no means 

 be confounded, as it often is, with the ultimate result — though, 

 in all probability, it represents a true genetic classification more 

 nearly than any other arrangement can do. 



I believe that the broad outlines of such a gradational classi- 

 fication of Birds may be sketched out with tolerable accuracy, 

 even though the details may have to be a good deal modified by 

 subsequent research. Thus I take it to be demonstrated that 

 the Tinamomorphce are those carinate birds which approach 

 nearest the Ratitcz ; and I think it may be shown that the great 

 majority of the Carinatce fall into one or other of four series, 

 which diverge directly, or indirectly, from the Tinamomorpha 

 as a common centre. 



Thus Turnix leads from the Tinamomorphce to the Charadrio- 

 morpha; and from the latter, two series start — the one com- 

 mencing with the Gulls and ending in the highly modified Pen- 

 guins, the other commencing with the Bustards and Cranes, and 

 ending in the highly modified Aetomorpha. On the other hand 

 Turnix leads to the Alectoromorpha, which is also the starting- 

 point of two series — the one commencing in Palamedea, including 

 the Chenomorphce, Amphimorphce, Pelargomorpha, and culmina- 

 ting in the highly specialized Dysporomoiphoi ; the other be- 

 ginning in Syrrhuptes and passing on to the Peristeromorphce. 



These series would stand thus, the names of the most dif- 

 ferentiated groups being in capitals : — 



