266 SCIENCE PROGRESS 



In addition to this humid melanism there is known to 

 exist a tendency towards blackness among certain species in 

 particular regions ; the blackness in this instance manifesting 

 itself only in a certain percentage of individuals. This 

 " dichroism " is particularly well exemplified in the case of the 

 snipe. Although this species ranges over a very large portion 

 of the Old World, out of fifty-five melanistic examples known 

 in collections (the so-called Gallinago sabinei), thirty-one were 

 killed in Ireland, twenty-two in England, one in Scotland, 

 and one on the Continent. Here, then, we have an interesting 

 case of the localisation and restriction to a humid region of 

 an occasional melanistic phase. An analogous instance is pre- 

 sented by the relative abundance of black leopards in the 

 warm damp forests of the Malay countries, from which probably 

 come nine out of every ten examples of the black phase. 



Next comes what may be termed casual or sporadic melanism, 

 in which individual members of a species or race turn black 

 altogether apart from locality or station. This type of melanism 

 is extremely common among cage-birds, and has been attributed 

 to special kinds of food, hemp-seed for example. According, 

 however, to Mr. A. G. Butler, food has nothing to do with the 

 matter ; and the phenomenon, which is most developed in old 

 birds, is more probably due to unusual constitutional vigour on 

 the part of such individuals. In this latter opinion Mr. Butler 

 expresses a view identical with one suggested by Prof. Einar 

 Lonnberg, of Upsala, to explain the development of blackness 

 in the adult males of many species of ruminant mammals ; a 

 development shared in certain cases by the females. 



Although there is no reference to it in Mr. Beebe's paper, 

 mention may also be made of what seems to be yet another 

 type of natural melanism. Some months ago I described — in 

 the Zoological Society's Proceedings — a tiger-cat from the Congo 

 forest as a distinct local race, characterised by its dusky colouring, 

 of a well-known species whose normal hue is either rufous or 

 grey. Shortly after the publication of the paper a specimen of 

 the same species living in the Society's menagerie changed from 

 red to dusky, thus demonstrating the slight value to be attached, 

 from a taxonomic point of view, to these colour-phases. That 

 the dusky phase is, however, connected with humidity cannot 

 for a moment be doubted ; but it has yet to be shown whether 

 the change from red to dusky is a character common to the 



