562 MURID^— MICROMYS 



duller than in winter, approaching the russet of Ridgway, but with a 

 tinge of rufous ; the sides dull cinnamon, the under parts dull ochraceous 

 buff, the median line having, however, especially about the chin and 

 throat, traces of white in the form of ill-defined lines and blotches ; the 

 line of demarcation inconspicuous, the feet and tail as in winter, but 

 more thinly haired, and therefore more obscurely coloured. It is quite 

 likely that were more mature material than that upon which these 

 descriptions are based available, rather more vivid hues would 

 be found to characterise both winter and summer coats than those 

 indicated here. 



Rope {pp. cit., 1884, 59) says that in the adults examined by him the 

 bright sandy yellow or orange fawn of the upper side was purest and 

 brightest towards the tail, on the hindquarters, and downwards towards 

 the vent ; this bright but delicate tint shaded off gradually into the 

 yellowish or orange brown of the upper parts generally, which latter 

 hue became brighter and lighter towards the white under-side. A 

 large male lacked the orange tint altogether, the upper parts being 

 nearly uniform brown, as in very old Brown Rats. Another male 

 had the mid-dorsum dark red-brown, inclining to purple, owing to the 

 unusual quantity of the long coarse dark hairs present. 



Sexual diflferences : — According to Darwin, the female of Mus 

 minutus is of a paler and dirtier tint than the male^ ; Rope {Zoologist, 

 1884, 59), however, fancies "the brilliant fawn tint "is most pronounced, 

 as a rule, in females. 



The young are duller coloured, more like House Mice in appearance 

 than the adults. Harting {Zoologist, 1895, 421) observed some young, 

 from Sussex, born in captivity ; these, even when almost as large as 

 the old ones, were not nearly so red. Indeed, until the beginning of 

 December they resembled a House Mouse in colour. About that time, 

 however, they began to change visibly, the hindquarters, from the root 

 of the tail upwards, becoming rufous before any other portion of the 

 body. Two young with Millais (174) began to assume the adult pelage 

 in January. 



Variation : — Tomes (in Bell, ii., 292) records the following variations — 

 one from Warwickshire had the whole upper side of a dirty sulphur- 

 yellow, the under parts as usual. One kept in confinement for a 

 considerable time and fed on hemp seed became eventually " very much 

 mottled with dark brown on the back " ; it was then fed for several 

 months exclusively on hemp-seed, but no further change took place. 

 Perhaps speaking of the same case. Tomes mentions elsewhere 

 ( Worcestershire) one, which fed on hemp-seed, '' changed from the usual 

 yellow to a deep red chestnut colour." 



Skull and teeth : — Apart from its small size, the delicate skull of 



' 7"^!? Descent of Man, ed. li. (25th 1000, 1889), 534. 



