372 ITS DISTINCTION FROM OTHERS. 
recent comparisons between certain species of ani- 
mals generally imagined as common to England 
and the Continent, have shown that sufficient 
differences exist to warrant a separation into 
species. But until this sort of enquiry has been 
applied to the Meadow Mouse, it is manifestly in- 
correct in writers to rest their specific characters of 
that animal on its dimensions, thus Fleming charac- 
terizes the Water Vole and the Field Vole or 
Meadow Mouse on the dichotomous method in this 
way ;— Water Vole, body 7 inches long, tail 3 inches. 
Field Vole, body 3 inches and ahalflong, tail 13inch. 
Now, if the reputed varieties of this latter animal 
are not distinct species, the dimensions here given 
are not descriptive of the animal! In his account 
of the latter, he says also that “ zt never exceeds 
half the size of the former.” Bingley says that “in 
England it usually measures to the root of the tail 
six inches, while in France it seldom measures more 
than three”; authors generally agree in the tail being 
no more than 13 inch long. Some writers so far 
from agreeing with Fleming in making dimensions 
of primary importance in the description, have from 
its great uncertainty, omitted it altogether. In this 
neighbourhood [have found that the Meadow Mouse 
usually measures from nose to tail about 33 inches, 
but a specimen I obtained from Whitney in Oxford- 
shire measured from nose to tail 42 inches; tail 
13 inch ; a specimen also belonging to G. Leach, esq. 
of Stoke, and taken in Devon, measures in the 
head 1} in., in the body 3 in., and in the tail 2 in. 
excluding the little pencil. ‘There are some other 
respectsin which the reputed varieties of this animal 
differ, but they are not so very important or suffi- 
ciently clear to be noticed here. When variableness 
of size does not obscure the characters of animals, 
the size and shape of the cranium form excellent 
distinctive marks. 
