RIDGWAY ORNITHOLOGICAL CLUB. 67 



del" the head of leucoderma, which is an acquired disease, while 

 albinism is a congenital abnormality. 



In reference to the latter conjecture I would say that I am of 

 the opinion that the finding of tcejiice in the intestines has no bear- 

 ing whatsoever upon the question, although I am forced to admit 

 that I at one time thought it had. However, I have dissected quite 

 a number of albinos in the last few years, and I have found very 

 few instances of any organic trouble or the presence of tape-worms. 

 Further than this I have found in a number of instances, that tape- 

 worms existed in birds of normal plumage, and as the latter cases 

 greatly outnumber those in which the plumage was albinistic, I 

 have become convinced that it was merely a coincidence and had no 

 effect upon the outward condition. 



I remember a case where in a perfectly white Cowbird [AIolo- 

 thrus ater) the sexual organs had been totally destroyed by a small 

 white worm which was, when discovered, imbedded in the supra- 

 renal capsule. Another case, which I dissected in the Spring of 

 1886, was an albino Lesser Scaup Duck {Aythya affinis). In this 

 instance I could at first find no traces of the sexual organs what- 

 ever, a careful search with a good glass being at last rewarded bv 

 my finding an ovary. This was very small, smaller even than you 

 would be likely to find in the Mniotiltidce in Winter. However, I 

 do not consider that the albinistic state of the plumage was in any 

 way brought about by this fact. I then regarded it, and do still, 

 as merely a case of non-development. I have also found worms in 

 the kidneys of birds of normal plumage, one, a White-throated 

 Sparrow {^Zonotrichia albicollis)^ which I shot last Spring, was in 

 the same condition as the Cowbird spoken of above, and yet the 

 plumage was perfectly normal. Other cases are those of the Wil- 

 low Thrush {Turdus fuscescens salicicolus) and Oregon Junco 

 {Junco hyemalis oi'egomis) which were shot in Chicago by my 

 friend Mr. H. K. Coale. Both of these birds had worms in the 

 kidneys and the sexual organs had completely disappeared, but 

 they were, nevertheless, in normal dress. 



In short I regard albinism as merely a congenital abnormality 

 having no physiological significance. 



Dr. Fox* says "in polar regions an absence of pigment is the 

 rule rather than the exception. This being the case it seems strange 

 that in the human race albinism should occur with perhaps the 

 greatest frequency in regions near the equator." 



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



