66 RIDGWAY ORNITHOLOGICAL CLUB. 



at least, to be in favor of the males by eight and two-thirds (82^) 

 per cent. Of course this is hardly an extensive enough test to settle 

 the question satisfactorily, and different persons might arrive at dif- 

 ferent results for this reason. I have observed that in taking land 

 birds only, the males will average a trifle over fifty-seven (57) per 

 cent., and the females a trifle over forty-two (42) per cent., while 

 among the water birds the averages that I have obtained are males 

 thirty-eight (38) per cent, and females sixty-two (62) per cent. 



Partial albinism is spoken of by Dr. Fox* as follows: " Part- 

 ial albinism is frequently seen in this country among the Southern 

 negroes, and some present the appearance of a piebald circus horse. 

 The white spot, or spots remain through life without change of size 

 or tint. The affection is rarely, if ever, met with in the white race." 

 He further saysf "it is said that albinism is not uncommon among 

 the negroes of Equatorial Africa, but I imagine that these white 

 negroes, to whom the Portugese sailors first applied the term albino, 

 were cases of leucoderma in which white patches (not congenital) 

 gradually spread until no pigmented skin was left." 



Another authority^ speaking of partial albinism says, " their con- 

 dition can probably be accounted for by some circumstances after 

 birth which will account for the change in the color of the skin, 

 such for instance, as the case given by the writer in the Oologist, in 

 which the skin has been injured on the back of a Swift, and the 

 next year the patch of white feathers indicated the situation of 

 the injury. The same thing is familiar in the case of the horse 

 whose back or shoulder is galled by the harness; white patches ap- 

 pear owing to the lowered vitality of the injured part." The article 

 then goes on to give as a possible cause of partial albinism the fact 

 that in four .specimens taken by the writer (a Black Squirrel with 

 a white tail and some white about the head, and partially white speci- 

 mens of Merula migratoria, Agelaius fhceniceus and Anas boschas) 

 he has found tape-worms (Tcenia solium). He also adds that "the 

 above may have been merely coincidences; still it has been observed 

 sufficiently often to make the fact suspicious as a cause of albinism." 

 In regard to the first point, although admitting that such cases 

 sometimes occur, I do not think that they do so sufficiently often in 

 birds to cut any figure whatever in the production of albinism, and 

 furthermore, from a medical standpoint, such cases would come un- 



*Photographic Illustrations of Skin Diseases, by Geo. Henry Fox, M.D. Chap. V, p. 140. 



tin epist. 



%G. A. M'Callum. The Auk. Vol. II, i8Ss, pp. 113 & "4- 



