I. Sexual, individual, and geographical variation in leucosticte tephrocotis, II.Geographical variation among North American mammals, especially in respect to size

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Abstract

Having recently had an opportunity (through the kindness of Professor Baird) of studying with some care the magnificent series of skulls of the North American Mammalia belonging to the National Museum (amounting often to eighty or a hundred specimens of a single species), I have been strongly impressed with the different degrees of variability exhibited by the representatives of the species and genera of even the same family. The variation in size, for instance, with latitude, in the Wolves and Foxes is surprisingly great, amounting in some species (as will be shown later) to 25 per cent. of the average size of the species, while in other species of the Ferae it is almost nil. Contrary to the general supposition, the variation in size among representatives of the same species is not always a decrease with the decrease of the latitude of the locality, but is in some cases exactly the reverse, in some species there being a very considerable and indisputable increase southward. This, for instance, is very markedly true of some species of Felis and in Procyon lotor. Consequently, the very generally-received impression that in North America the species of Mammalia diminish in size southward, or with the decrease in the latitude (and altitude) of the locality, requires modification. While such is generally the case, the reverse of this too often occurs, with occasional instances also of a total absence of variation in size with locality, to be considered as forming "the exceptions" necessary to "prove the rule".

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Additional publication details

Publication type Report
Publication Subtype USGS Unnumbered Series
Title I. Sexual, individual, and geographical variation in leucosticte tephrocotis, II.Geographical variation among North American mammals, especially in respect to size
DOI 10.3133/70157321
Volume II
Issue 4
Year Published 1876
Language English
Publisher Government Printing Office
Publisher location Washington, D.C.
Contributing office(s) U.S. Geological and Geographical Survey of the Territories
Description 43 p.
Larger Work Title Bulletin of the United States Geological and Geographical Survey of the Territories
First page 309
Last page 350
Country United States, Canada, Mexico
Other Geospatial North America
Online Only (Y/N) N
Additional Online Files (Y/N) N
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