116 STRUCTURE AND COMPARISON. 



common, nor are white blackbirds, as has been said. I have 

 seen a white ineadow-lark also almost pure white with only a 

 faint yellow tinge on the breast, yet I have never heard of 

 an albino among the jays and orioles, though they are nearly 

 related. Ducks are frequently albinistic, and so are quail and 

 grouse; but hawks are rarely, if ever, affected in this way. 

 Sparrows are another family among which albinos are com- 

 mon. I have had a snow-white eaves swallow brought to me, 

 and have seen a cherry bird all white except the yellow tip of 

 the tail. Thrushes also not infrequently show signs of albi- 

 nism, but I have never seen an albino warbler nor a white fly- 

 catcher. This is not saying that these freaks will not be 

 discovered by sharp eyes; rather it shows that in certain 

 groups the accident is rarer than in others. 



Even rarer than albinism and certainly far prettier is an 

 occasional paleness of plumage that gives the whole bird a 

 delicate cafe-au-lait color just the shade of coffee with cream 

 I have seen this in ducks, and a remarkable case of it in a robin, 

 where the whole head and upper parts were delicate creamy 

 brown, while the breast was as red as in an ordinary robin. 



Another accident sometimes noticed is just the reverse of 

 albinism. Instead of being white, the bird is black or much 

 darker colored than usual, sometimes a dark chocolate or 

 deep blackish brown. This is called melanism, from the Greek 

 word for black, just as albinism comes from the Latin for white. 

 Melanism is most frequent among the hawks, which so seldom 

 show traces of unusual whiteness. In certain hawks, as the 

 red-tailed, Swainson's, and the rough-legged, this occurs so 

 often that it is probably not an accident, but a " color phase." 

 Eobins are particularly subject to melanotic changes. Some- 

 times they have been' reported " as black as grackles." 



While albinism seems to be permanent, melanism is not 



