THE BANK MOUSE 417 



from March to December inclusive, and probably includes also 

 not infrequently January and February. Mr Adams gives the 

 average of twenty litters as 3 "8 young; he has examined in 

 all 2 of six, 6 of five, 15 of four, 13 of three, and 2 of two. 

 Very probably these figures include the litters of young mothers, 

 and of unfavourable seasons. A series examined in the height 

 of the sexual season should give larger results, and Mr Cocks 

 reports a litter of eight found on 27th May 191 1. 



The nurseries may be found, usually above ground, in 

 hedgerows or hayfields. They are composed of grass, the 

 interior bitten fine,^ and a lining of moss, sheep's wool, or 

 feathers ^ may be added ; thus serving to distinguish the struc- 

 ture from that of the Grass Mouse, which only uses such 

 luxurious materials in winter. Collett mentions a Norwegian 

 nest which was placed on the roof of a house at a height of 

 nearly 20 ft. ; another was built into that of a Fieldfare, at 

 6 ft. from the ground, in a young spruce ; it was domed, with 

 a small entrance near the under side. 



According to observations made on captives, young were 

 observed with the eyes open on the fifth day from birth, at which 

 time they were clothed with blackish down, and their whiskers 

 began to show ; on the seventh day they were brownish.* The 

 members of another litter * began to move about when eleven 

 days old, and at fourteen days were fully furred, active, and 

 able to feed themselves. 



Bank Mice have frequently been kept in captivity, and 

 evidently vary much in individual disposition, being some- 

 times described as inoffensive and amiable, at others as shy, 

 irreconcilable, and easily provoked to bite. Macpherson, for 

 instance, had two, of which one was sullen and untamable ; 

 the other, which had a charming temperament, was eventually 

 murdered and eaten by its companion. They are fond of 

 preening their fur. They sleep with the head tucked away 

 under the belly between the fore paws, and sometimes make a 



' English's captives cut stiff hay into lengths of i inch or less, which then gained 

 breadth by splitting of themselves longitudinally. 



2 Fatio. 



^ English ; the first date is so very early, that an error may be suspected, and it 

 would be desirable to have confirmation of any date earlier than the eleventh day. 



* T. V. Roberts, Zoologist, 1892, 329 ; see also Nature Notes, 1903, 130. 



