BRITISH MAMMALS 
for some time in captivity were very clever in catching any small 
flies which entered their cage, when they were promptly seized and 
eaten. 
These mice make interesting and cleanly little pets, and soon get 
accustomed to captivity. 
THE WOOD MOUSE. 
Mus sylvaiicus, Linnaeus. 
Plate 26. 
The Wood Mouse, also known as the Field Mouse or Long-tailed 
Field Mouse, is subject to great variation in size and colour which has 
led modern naturalists to sub-divide it into many local varieties or sub- 
species. It is one of the most common and widely distributed of British 
mammals. 
The prevalent form inhabiting our islands (the Mus sylvaticus inter- 
medins of Millais) has in general a length in head and body of 3^ inches, 
with about the same measurement for the tail. The colour of the upper 
parts is a yellowish brown, brighter on the cheeks and along the lower 
part of the ribs, and shaded with blackish hairs which are most distinct 
about the back. The basal portion of the fur is dark slate colour. The 
under parts are white or greyish white with usually a breast-spot of a 
buffish tint. The feet are light greyish flesh colour. 
The young are always much greyer and duller in colour. 
This species is easily distinguished from the Common House Mouse, 
apart from its brighter colouring, by the large prominent black eyes and 
much longer ears, hind legs, and tail. In general, the Wood Mouse 
has also a more thoroughbred look than the other. 
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