ALLEN. — THE HEREDITY OF COAT COLOR IN MICE. 65 



of France, a half century ago, and other instances of their appearance 

 here and there might be cited. The (juestion may be raised, however, 

 as to the likelihood of such spoi-ailic cases being due to the introduction 

 of albinos from other sources, and their subsequent escape. Never- 

 theless it is a matter of common knowledge that albinos may occur 

 dc iiaro among many S|)ecies of inamnials, as in deer, bison, s(|uirrels, 

 moles, and others (see Cantoni, '80). 



It is thus not dillii-ult to conceive how the albino and the Itlack bi'eeds 

 now domesticated have originated. But the origin ot other fancy varie- 

 ties is not so clear. Thus Pallas (; 78) mentions three varieties : the 

 albino with pink eyes, a black variety, and one gray with white spots. 

 J. B. Fischer ('29) enumerates five diiferent varieties of the house 

 mouse : '' totus albus oculis rubicundis," '' totus niger," " albo-macula- 

 tus," " helvolus," " albus cinereo-maculatus." The first three varieties 

 mentioned probably correspond with those recognized by Pallas ; namely 

 albino, black, and gray-white ([)erhaps also black-white). The two new 

 varieties in Fischer's list are: (1) " helvolus," supposed by C. Carter 

 Blake (in P^'ancy Mice) to be the same as isabella (yellow) and (2) " albus 

 cinereo-maculatus," that is, wliite spotted with gray. Dehne ('55), writing 

 of the house mouse found in Europe, mentions mice of the usual gray 

 color above, but varying in the color of the belly from pure white to 

 yellowish. The albino, he says, is common, though formerly a rarity. 

 He mentions also a light yellow (•' erbsen gelb") variety, with ^^m/l' 

 eyes, and a gray-white spotted variety. 



The origin of the spotted varieties is unknown. Swinhoe ('70), in 

 writing of the mammals of China and Formosa, states that black-white 

 mice are often kept by the Chinese and that " these are brought from 

 the Straits."' The so-called dancing mice are usually attributed to Japan. 

 They are smaller, and of more delicate proportions than the wild house 

 mouse or its tame European varieties, and if actually of Japanese origin, 

 may have been derived from one of the indigenous species closely related 

 to Jllus miisculns. Ordinary dancing mice are black-white, but there occur 

 also individuals which are wholly black or white, or which are spotted fawn- 

 and-white,and have pink eyes (Darbishire, : 02). They are called dancing 

 mice from a habit which they have of turning rapidly in circles of vary- 

 ing diameter, the direction of motion being usually clockwise. This 

 habit is by some attributed to a nervous disorder, and by others to an 

 abnormality of the semicircular canals of the ear. It is termed by the 

 Fi-ench " mouvement de manege". This breed is believed to have been 

 domesticated by the Japanese for a considerable period, as evidence of 



