14 Zoologia: N. Y. Zoological Society. [Vol. I 



wholly replaced with rufous in the other phase. In the dark bird, 

 blue barring has appeared on the under primary coverts and 

 subterminal spots on the feathers of the sides, while the entire 

 under parts, from throat to tail coverts, is a deep cinnamon, very 

 different from the white, slightly rusty-tinged, ventral feather- 

 ing of the light bird. 



Our knowledge of these two forms in the living wild state is 

 very meagre. They have been known to breed together, and 

 young birds of both colors have been found in the same nest, 

 but Mr. Chapman records that of all the pairs he observed breed- 

 ing in Cuba, in no case was a dark bird paired with a light 

 one, or vice versa. The most interesting fact in regard to this 

 dichromatic species is its extreme localization. Closely related 

 forms of Falco are found throughout the other West India 

 Islands and in most of North and South America, and yet outside 

 of Cuba there is no tendency shown to develop distinct color 

 phases. 



To refer parenthetically to geographical melanism in the 

 mammalia, we find a number of examples paralleling in many 

 respects the avian case of Gallinago. Partial and wholly melan- 

 istic individuals of the jaguar, Felis onca, are not uncommon in 

 northern South America, being most abundant, according to 

 Humboldt, in the humid region of the Orinoco, while to the south- 

 ward these animals become more yellowish or even whitish in 

 color. It was formerly thought that this dark phase was a dis- 

 tinct species and the name Felis nigra was given to it by Erxle- 

 ben. The best known case of melanism among mammals is the 

 leopard, Felis pardus. Intermediate phases are rare, the melan- 

 ism being usually so complete that the entire animal is uniformly 

 black, the rosettes being visible only in certain lights. In the 

 northern part of the leopard's range in Asia the black phase 

 is unknown, but in the southern, more humid regions, the number 

 increases until the center of their occurrence is reached in Singa- 

 pore; Assam, Sumatra and the Malay Peninsula being the home 

 of nine out of ten of these animals. I can discover only six refer- 

 ences to melanistic individuals of the leopard in South Africa. 

 The name Felis melas has been applied to the black leopards, but 

 there is no question of the specific identity of these and the nor- 

 mally colored individuals, since the occurrence of both spotted 

 and black cubs in the same litter has been again and again 

 recorded. 



One of the most interesting cases among the mammalia, and 

 one for which at present we can offer no satisfactory explana- 

 tion, is that of the big-horn or mountain sheep of western North 



