282 CHAPTERS ON THE NATURAL HISTORY 



ing out that the pterylosis differed in the several families aud 

 orders of the class. A great continental naturalist, Nitzsch, has 

 done more for us in this direction than any one else, and I may 

 add that the pterylosis of a great many of our United States 

 birds remains yet to be described, and that, too, in many impor- 

 tant forms demanding a more correct classification than has 

 thus far been awarded them. Further on I will demonstrate this 

 latter statement by an example, and as the pterylosis of 

 a bird with due care can easily be described and worked out, it is 

 the chief object of this part of the present chapter to excite the 

 interest of naturalists and others in this subject, with the hope 

 that further investigation in the field will be duly undertaken. 



Nitzsch employed four principal methods of studying the ptery- 

 olsis of a bird: |i) by examining nestlings; (2) by plucking adult 

 specimens; (3) by clipping off all the feathers, wetting the body, 

 and then examining it; and (1) by skinning the bird, and studying 

 the pterylw and apteria upon the inner surface of the skin. 



In the present connection it is not the writer's intention to en- 

 ter upon the subject of the study of the structure of the numer- 

 ous forms that feathers themselves are known to assume, for as 

 interesting as this is, space alone would prevent such a step here. 

 Nor do I intend to dwell, and for the same reason, for any length 

 upon the arrangement or number of the feathers-in-chief of the 

 wings (remiges) or the tail (rectrices), both of which are known 

 to be so various in birds. Much less do I intend to enter upon 

 the character of plumage itself, and the fantastic variations it 

 may display in a great many of the representatives of the Class. 



On the other hand, I shall aim to present the several names 

 which have been bestowed upon the feather-tracts, to designate 

 them; and by pointing them out by the aid of my drawings, here- 

 with presented, show their relative position in one of our birds; 

 and finally will offer another bird, nearly related, and with ap- 

 propriate figures endeavor to point out the value of pterylosis in 

 classification. 



By this means I hope to lay a safe guide before any one, who 

 in the future may have the opportunity to study the pterylosis 

 of our birds, and especially in those forms which, up to the pres- 

 ent writing, have not fallen into the hands of science except in 

 dried skins, which are useless for such purposes. 



Any accurately recorded pterylographical notes are of the high- 

 est importance to the science of ornithology. 



