592 MURIDAZ—EPIMYS 
vestigial and may be wholly absent; 2, appears to be rather more 
simplified than in orvegicus, but the posterior lobe when quite unworn 
shows distinct traces of cusps 4 and y. 
Exceptional variation :—Individuals with a white chest spot, some- 
times of very large size, or a median stripe of white, are not infrequent 
in &. r. rattus, and have been observed at Yarmouth by Patterson ; 
similarly, individuals with a dusky patch or stripe are often found 
among the light-bellied forms. From the experimental breeding of 
norvegicus performed by Crampe, Doncaster, and Mudge, it would 
appear that such patterns are the subjects of Mendelian inheritance 
independently of the colour. A  white-spotted 7 vattus, from 
Kongsberg, Norway, has been recorded by Collett. Rarely, an 
ochraceous patch is seen on the ventral surface just behind either the 
right or the left fore limb (B.M., Nos. 1.11.3.26, Brazil, alexandrinus ; 
8.9.12.2, British New Guinea, va¢tus,; both males). In some forms, 
particularly in the young, a white spot is present on the forehead: 
on such a variation from the Punjab, W/us brahminicus of Lloyd (Ree. 
Indian Mus., iii., 1909, 22) is based; Fatio (p. 199) describes, from the 
neighbourhood of Geneva, a colony of Black Rats in which, young and 
old alike, all were characterised for many consecutive years by the 
presence of a conspicuous white lock on the centre of the forehead. 
Albino specimens have been known from the time of Gesner (see 
Kolazy, Verh. Zool.-bot. Ges., Wien. 1871, 731, and below under xor- 
vegicus). According to Patterson (Zoologist, 1907, 69), a male from 
Yarmouth was of a very pale blue-white colour and. had fiery red eyes; 
its creamy white tail was rather shorter than usual. As is the case with 
norvegicus, a hairless variety, due to disease, is known (T. E. Belcher, 
Zoologist, 1904, 72; and J. Woodward, Fze/d, 19th August 1905, 378). 
Bellermann! said that “very often six to eight lie together and 
entwine their tails as closely as if they were fused with each other. 
Such a nest is called a ‘King Rat.” Blasius (319), repeating this 
curious statement, apparently on his own authority, says that the tails 
are fused, and that as such individuals are incapable of moving freely 
in the search for food, they must be fed by their parents or by other 
rats; hence the name Rattenkonzg. 
Geographical variation :—This species is represented in the Oriental 
region by a great number of named forms, but the status of many of 
these is still far from being satisfactorily determined. Oldfield Thomas 
(Proc. Zool. Soc., London, 1881, 533) arranged the Indian members of 
1 Daseyn des Rattenkiniges, 1820. Oken, Allgem. Naturgesch., 7, Abt. 2,719. A 
belief in “King Rats,” dating at least from Gesner (De Quadr., i., 829), is widely 
spread in Germany and in the German idiom, “ez Ratlenkinig von Unwahrschein- 
lichkeiten”=“a perfect maze of improbabilities” (see Muret-Sanders, Excyclop. 
Worterbuch ; J. and W. Grimm, Deutsches Worterbuch, 1893). Schreber, long ago, 
dismissed this belief as “a mere and very badly contrived fable.” 

