86 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Salviu, of England, and Mr. George K Lawrence, of New York City 

 (both of whom have kindly loaned me their entire series), I have been 

 enabled to bring together a collection amply sufficient to settle former 

 doubts. 



The inference derived from a careful study of the material first in 

 hand was, that a greater number of species existed than were usually 

 recognized as valid; certain forms allied to S. brasilianm (Gmel.), 

 named, but generally considered synonymous with some other spe- 

 cies, being i'ei)resented by typical specimens, while there were no exam- 

 ples of intermediate character, the differences between these several 

 styles being moreover so obvious that it seemed scarcely possible they 

 could iutergrade. I was therefore quite convinced that additional 

 material would confirm the view of their distinctness. Being thus 

 prejudiced, as it were, in my views of the relationship of the several 

 forms alluded to, 1 at first attempted to divide the new series accord- 

 ingly. Determined and repeated efforts failed, however, until 1 fully 

 realized the utter hopelessness of the attempt. Thus I was irresistibly, 

 though quite against my previous convictions, led to the same conclu- 

 sion as that reached by Messrs. Sclater and Salvin, and subsequently 

 adopted by Mr. Sharpe, that the several supposed species allied to tS\ 

 brasilianus are merely geographical, local, and individual variations of 

 the same species. No other view seems justifiable, in view of the com- 

 plete and unquestionable intergradation between the most extreme vari- 

 ations. The only alternative is to allow a very much greater number 

 of forms even than have been named, admitting at the same time the 

 intergradation of each with the other. 



It has been remarked by an eminent author* that few, if any, birds 

 vary more in their feral state, both individually and otherwise, than 

 the owls, and that of all the genera of this family the present one is 

 the most variable. In this opinion I fully agree, for I have rarely had 

 a more difficult and, I may say, more unsuccessful task than my attempt 

 to elucidate the several species and '•'races" treated in the present 

 memoir. 



In the first place, the plumage is characterized by confused markings 

 in the form of zigzags, " herriiig-boue" plctunv^ and minute vermicula- 

 tions, having much the same general character in all, the difference 

 between the several species in the pattfi-rn of coloration being exceed- 

 ingly difficult of description. Next, there is the perplexing condition 

 of "diehromatism", the same species having two very distinct phases 

 of plumage — a gray phase, which may be considered the normal dress, 

 and a rulous phase, which is an extreme development of the variation 

 called '• erythrism'". These two extreme phases, which it is to be remem- 

 bered do not depend at all upon age, sex, or season, being purely an 

 individual peculiarity, are in each species so very unlike that corre- 

 sponding phases of the several really distinct species resemble one 



*^ Sharpe, /. r.. p. 44. 



