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 ro1rt. 
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 1 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. 
