^"'ioi?^^] Trotter, Relation of Genera to Faunal Areas. 159 



In June or May sometime Batchelder sent me three young 

 Screech Owls. I sent them up to Chocorua. They were grey and 

 lovely but with awful tempers and harsh voices. Two were later 

 returned to him, and again sent up to Crowlands. They had lost 

 their good feeling toward the one left with me and abused him 

 somewhat, shunned him always. At last, late in August I think 

 it was, I found him dead and plucked in the cage. x\ week or two 

 later I put the survivors into a barrel with a live mouse. Neither 

 caught it. They quarreled and the next morning one of them was 

 dead and partly plucked. The day following the other died. I 

 clipped all of their wings and took out the one not returned to 

 Batchelder several times. He drew birds if they saw him but he 

 often made a stump of himself and evaded observation. They were 

 fond of small birds, mice, fish, and so-so of liver. 



THE RELATION OF GENERA TO FAUNAL AREAS. 



BY SPENCER TROTTER, SWARTHMORE COLLEGE, PENNSYLVANIA. 



Tpie relative antiquity of a genus is probably indicated by the 

 greater or less departure of its several species and their varietal 

 forms from a common ancestral type. The degree of departure 

 may be the resultant of two opposing factors — first, the influence 

 of conditions favoring segregation, as the character of the vegeta- 

 tion and the variety of habitat within the breeding range, and, 

 secondly, the opposing factor, that of the inherent quality of 

 resistance in the common ancestral type against the disrupting 

 influences of environment and of variational tendencies. It is 

 in the breeding ground or faunal area that we must look for the 

 conditions which produce these changes in epidermal tissue and 

 those minor departures in voice and habits that we recognize as 

 constituting distinctive specific and varietal differences within a 

 genus. These influences are operative in the breeding area at the 

 period of greatest plasticity of the organism, and variations from 



