LEPORIDE—GEOGRAPHICAL VARIATION, 269 
with locality is often less strongly marked than in many other groups, even 
among the Rodents. Taking as an illustration of this point one of our 
widest-ranging species, the little Wood-Hare (Lepus sy/vaticus and its several 
varieties), we find that specimens from the Carolinas, Georgia, and Florida 
are, in the average, not much darker than those from Southern New England, 
the difference being generally too small to give in itself a positive clue to 
the locality, as is so generally the case in birds, and often in other groups of 
mammals. Indeed, specimens from the Mexican provinces of Vera Cruz and 
Yucatan are in no way positively distinguishable from those obtained about 
Washington or in Massachusetts. 
On comparing, however, specimens from the Atlantic coast with others 
from the arid interior of the continent, we find the differences in color 
resulting from the different climatic conditions of the two regions are strongly 
marked, through the greater pallor of those inhabiting the dry plains and 
semi-desert portions of the Great Central Plateau. The bleaching effect of 
an arid climate is quite marked in specimens living as far east as Eastern 
Nebraska, while the greatest degree of pallor is seen in those inbabiting the 
Great Colorado Desert. Again, specimens from that portion of the Pacific 
slope north of California 
a region of heavy rain-fall and dense forests— 
present as dark or even a darker phase of coloration than those from the 
Atlantie States, just as proves to be the case in the wide-ranging species of 
the Sciuride and Muride. 
The same regional phases of color-variation are also illustrated by the 
Northern Hare (Lepus americanus and its varieties), which ranges ina similar 
way across the whole breadth of the continent. The increase in intensity 
of color from the north southward is rather more decidedly marked than in 
L. sylvaticus, in both its summer and winter conditions of pelage. Summer 
specimens from New England and the Middle States are of a much stronger 
ferruginous tint than those obtained during the same season from the arctic 
regions. Winter specimens differ in the more northern having the white 
color of the surface so deeply invading the pelage as to wholly conceal the 
brown under-fur, while in those from the extreme southern limit of its range 
the white is a mere slight superficial wash, by which the brown under-fur— 
of a stronger tint also than in the northern specimens—is only partly con- 
cealed, the white winter livery being often but imperfectly acquired at 
southern localities where it is always assumed for a much shorter period. 
