A STUDY IN THE VARIATIONS OF PROPORTIONS IN 
BATS, WITH BRIEF NOTES ON SOME OF 
THE SPECIES MENTIONED. 
BY HENRY L. WARJ>. 
Custodian of the Public Museum of the City of Milwaukee. 
In recent years much attention has been given to the verte¬ 
brate fauna of North America, and the number of more or less 
authoritatively recognized species has multiplied with great 
rapidity. In mammals this increase, as well as a general over¬ 
hauling of the nomenclature, has been accelerating from year to 
year. 
In 1885 there were recognized 363 land mammals from the 
North American Region; in August of the present year this 
number had increased to about 1,700 of which 304 were the 
result of the last twenty months. 
Much of this increase is due to the recognition of subspecies 
founded on more or less marked peculiarities shown by geo¬ 
graphical races. To clearly distinguish characters due to a 
particular habitat from those due to individual variation is con¬ 
sequently a matter of prime importance. To study individual 
variation successfully it is important that a large series of 
specimens from a particular locality be examined, and it is bet¬ 
ter that one person make all of the observations, measurements, 
etc., and as nearly as possible at one and the same time so that 
the conditions governing their accuracy may be as uniform as 
possible. 
Some years ago, when living in Mexico, my interest in bats 
was particularly active as I had several new species to describe. 
I had made considerable collections in various places, particu¬ 
larly in the states of Morelos and Veracruz, and the opportunity 
