iEgeriidse 
miles of species which are in many cases distinctly subtropical. 
On the high peaks holarctic genera occur, and in the valleys genera 
which have their metropolis in Mexico. In a general sense the 
territory may be called the Coloradan subregion. 
The Pacific subregion includes central and northern California 
and the valleys lying between the coast and the western outliers 
of the central cordillera. The subregion extends northward into 
British Columbia. There is shown here a distinct resemblance to 
the fauna of Europe and temperate Asia. 
Beginning in Labrador on the east and extending across the 
entire northern portion of the continent into Alaska is a region 
which we may call the Holarctic subregion, in which the genera 
and species alike of plants and animals are for the most part the 
same which are found in similar latitudes in the Eastern Hemi¬ 
sphere. In Alaska there is evidence of a distinct connection be¬ 
tween the flora and fauna of Asia. Greenland and Labrador, 
together with some of the adjacent islands, show remarkable 
affinities to the flora and fauna of boreal Europe and the Alps. 
Various subdivisions of these broader areas have been sug¬ 
gested, but in the main the subregions which the writer has 
indicated suffice to show the differences in these tracts. 
**. . . From every chink 
And secret corner, where they slept away 
The wintry storms—or rising from their tombs 
To higher life—by myriads, forth at once, 
Swarming they pour, of all the varied hues 
Their beauty-beaming parent can disclose. 
Ten thousand forms ! ten thousand different tribes ! 
People the blaze.” 
Thomson. —Summer. 
390 
