630 MURIDAZ—EPIMYS 
belong to the present species. The behaviour of tame 
norvegicus has been well described by Lataste, from whose 
account the following particulars are largely drawn. They are 
nocturnal and omnivorous; lying in the nest curled up, the 
head on chest, and sometimes vertically. They form stores 
of provisions in their nests, females sometimes stealing the 
goods of their spouses. Lataste describes it as the most 
intelligent rodent examined, recognising its owner, licking him 
and pretending to bite like a puppy; it can be trained to draw 
up food or drink with a chain, and to count up to four. Wild 
rats are difficult to tame, being very fierce and intractable, 
unless taken very young. They are variable in individual 
character though usually friendly to each other, unless their 
sense of property be violated. They are prudent without being 
cowardly, and are much superior in brain to either Black 
or Water Rats. Although so big and heavy they are still very 
agile, and Lataste has killed them on the summits of the 
highest Palms. They swim habitually, although their aquatic 
powers are very inferior to those of the Water Rat. They are 
“chard” rats—a fall of 2 metres causing no injury. They never 
beat with the feet like Gerbillines, but utter cries when battling 
or coupling ; Lataste describes the cry of grief as sec et désagré- 
able, The rut lasts only a few hours, and they are more violent 
in coupling than are tame mice. Gestation lasts twenty-two 
days, and is apparently unaffected by lactation. A few days 
before the end of gestation the female prepares a new nest for 
her family, and later she behaves as an excellent mother. The 
male kills and devours strange young, but respects those 
of a female with whom he has coupled; these he regards with 
seeming indifference—perhaps only on account of the maternal 
jealousy, for he has been known to help in transporting them 
when occasion required. 
Lataste (373-375) describes the post-natal development. 
From his account it would appear that at the sixth day the 
pink colour of the young rat changes, indicating the develop- 
ment of hair. On the tenth day the back is white and 
covered with fine hairs of 1 mm. in length; at the fourteenth 
day the eyes open, and on the sixteenth day the perforation of 
the outer ear appears. On the seventeenth or eighteenth day 
