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THE AMERICA N \\ ITUBAL IS T [ Vol. XL VIII 



robins and a white-spotted bee-eater with a flock of its 

 brethren, in both cases wholly at peace. This of course 

 was in flocking time when the social spirit is strong. The 

 song sparrow {Mrtospizu) with white outer tail feathers, 

 previously mentioned, was attacked and driven off by 

 another song sparrow. In the Journal of the Maine 

 Ornithological Society (Vol. 6, p. 48, 1904), C. H. Clark 

 writes of a pair of albino cave swallows (Petroclielidon 

 lunifrons), at Lubec, Maine, 



among a largo colony of the common ones who seemed greatly annoyed 

 at the albinos' presence and fought with them until they finally killed 

 one ... or rather injured it so hadly that il died soon after. 



I also have a note of a white robin at Montclair, N. J., 

 which in early July, 1909, was seen to be much beaten and 

 driven about by another robin and eventually flew at full 

 speed against a tree and was killed. 



Centrifugal Coloration 



In addition to the primary pigment patches which I 

 have discussed at some length, and the speckled condition 

 or "English" marking, there is, as I have already inti- 

 mated, a third condition in which pigment is developed 

 at the extremities or points. It maybe called a centrifugal 

 type and is almost the reverse of the centripetal or "pri- 

 mary-patch" class. 



The two latter types of pigmentation may both be 

 found in the same individual, but ordinarily this is not 

 evident except in cases where the primary patches are 

 somewhat restricted in area. It then may become appar- 

 ent that pigment is present at exactly those points where, 

 in the centripetal type of coloring, it is first to be lacking. 

 Moreover it persists strongly, even though the primary 

 areas are much reduced or largely absent. Curiously 

 this sort of pigment seems almost always to be black. 

 Apparently centrifugal pigmentation does not occur in 

 all species. I have never seen any trace of it in dogs. 

 In the house cat it is frequent, however. Thus in Figs. 



