To the author this white spot on the boreal horn of Venus does not appear to be due to an effect of contrast, as has sometimes been supposed.
It is a curious fact that terrestrial magnetism and the boreal auroras exhibit an oscillation parallel to that of the solar spots, and apparently the same occurs with regard to temperature.
Hudsonian zone: is that part of the boreal region comprising the northern part of the great transcontinental coniferous forests.
Chiefly a boreal species, especially during the breeding-season, the Red-throated Diver is only known to visit us during the winter.
The Razor-billed Auc, owing to its boreal residence, is not so well known as many other marine species which breed nearer home.
In these mountains and in the boreal mountainous parts of the intervening region of the United States, erminea and the large-sized frenata occur together over a wide area.
Transition and Boreal life-zones of Siskiyou and Trinity mountains in southern Oregon and northwestern California.
Temperature, it seems, causes the hair to vary; the pelage is harsher and sparser in weasels from tropical regions than in those from boreal regions.
Tropical Life-zone, probably into Boreal life-zones, of mountains along eastern border of southern Veracruz.
The assemblage of mammals from Conard Fissure includes several species of boreal predilections which, like Mustela erminea, now occur only much farther north than Arkansas.
He is a hardy navigator," continued Kurz Pacha, "who sails for the boreal pole.
A few boreal species construct loose coverings of threads of silk at the roots of grasses, and here undergo their transformations.
Pelidne is rather abundant in Labrador at the proper season, and ranges thence westward and northward in boreal America.
There are two or three other species of this obscure genus, but they are rare boreal insects, of which little is as yet known.
There are about twenty-seven species of this genus found within the limits of boreal America.
It is, like all its congeners, an alpine or boreal species.
In spite of the fact that these insects are boreal or arctic in their habits, Mr. W.
This species is boreal in its haunts, and is found in New England and northward and westward into the British possessions.
This species, originally described from Labrador, is found throughout boreal America and British Columbia.
With the coming of the Dicotyledons, therefore, the vast temperate and boreal regions presented a particularly favorable field, which they have entered and taken possession of.
This vast group is prominently adapted to living in the unoccupied temperate and boreal regions.
In the late Tertiary, and especially in the Pleistocene, animals known to have made migrations between North America and Asia were types now characteristic of boreal climates (e.
He states that there is good evidence that these are all mainly warm-climate animals which are not likely to have ranged in any force into a cold-temperate or boreal environment.
Major results of this include isolation of certain populations and absence of others in the boreal islands.
A borealforest on the higher slopes of the mountains of southeastern Coahuila is suitable for certain northern birds such as Goshawks, Pine Siskins, and Brown Creepers.
Glaciers retreated or disappeared, boreal forests became montane in much of the United States, and the lakes in the Great Basin were reduced or disappeared.
A number of other boreal mammals have geographic ranges which resemble that of Sorex vagrans, except that the geographic ranges of subspecies do not overlap.
In the ensuing Sangamonian interglacial age all glaciers retreated or disappeared thereby opening up extensive areas in the north and in the higher mountains which were occupied by a boreal fauna, including S.
Red squirrels do not occur on any of the boreal montane "islands" of Nevada.
Because of the general similarities of these geographic ranges, it is pertinent to examine the reasons suggested by students to account for the present geographic distributions of some of these other boreal species.
In addition, the vegetational zones are found at lower elevations, and there are boreal forests in the lowlands rather than only in the mountains as is the case in Utah and Colorado.
Glacial ages, characterized by extensive and continuous areas of boreal habitat, probably were times of relatively unrestricted gene flow between many populations of boreal mammals and hence not favorable to rapid speciation.
There were boreal forests at lower elevations than there are today in comparable latitudes and continuous boreal habitat probably connected many of the isolated mountain ranges of the southwest.
These grouse thus seem to offer additional evidence for a Pleistocene, possibly Wisconsinan, separation of the boreal fauna into a Rocky Mountain and a Pacific coastal segment.
One can envision that during such times boreal mammals were isolated, their geographic ranges were restricted, and Sonoran mammals expanded their ranges.
That probability is supported by the presence ofboreal animals and plants on many of these isolated ranges today.
No Clethrionomys are found in the Sierra Nevada, nor are red-backed mice found in the boreal islands of the Great Basin.
They are generally regarded as periods of warmth and aridity and, therefore, probably are times of segmentation of the ranges of boreal mammals and hence times exceptionally favorable to the process of speciation.
Around the point in the heaven which corresponds to the direction of the dipping needle produced, the rays appear to meet and form the boreal corona.
The 47 species from the Mesa Verde that are not exclusively boreal make up 87 per cent of the mammalian fauna.
It is evident that what would be necessary again to envelop the boreal parts of North America with a glacial sheet would not be a considerable decrease of heat, but an increase in the winter's contribution of frozen water.
Applying this principle to the northern hemisphere, we can in a way imagine a change which would probably bring about a return of such an ice period as that from which the boreal realm is now escaping.
These are well defined and important in the tropical, austral, and transitional, but less definite and less well known in the boreal and arctic provinces.
Like the boreal forest, the one under consideration is largely composed of coniferous trees, although in the valley, and especially along the borders of streams in southern Canada, Washington, etc.
In the main or northern portion of the boreal province, owing to the comparatively high latitude, the variation in the number of hours of light and darkness each day during a year becomes conspicuous.
In spite of the great area covered by the boreal forest, it being one of the greatest, if not the most widely extended continuous growth of arboreal vegetation in the world, it is of comparatively small economic importance.
In the northern portion of the Rocky Mountain region in Canada and Alaska the boreal forest, as already stated, merges by insensible gradations with the forests occupying the Pacific mountains from Alaska southward to Mexico.
With the northward sweep of the waves of bird life over the temperate and boreal portions of the continent comes the awakening of plant life, but the birds, to a marked extent, precede the unfolding of the flowers.
This, the transition region between the austral and boreal provinces, includes the cool temperate portions of North America.
Peninsula-like and island-like areas occupied by the boreal forest occur in the sea-like expanse of the transition and austral provinces, on both the Atlantic and Pacific mountains.
The winters are longer and more severe than in the boreal province, and the summers short and hot.
Both the Atlantic and Pacific forests merge at the north with the boreal forest, which extends diagonally across the continent from Newfoundland to Alaska.
But the seventeenth, eighteenth, and nineteenth centuries passed and left the "Boreal Center" undiscovered.
The Romantic School,'the audaciousboreal school,' had appeared.
Barren as the soil might be, he did not despair of growing there under this ray of beauty and of grace, which came directly from the great boreal sun; and in truth he kept this post at Stuttgart for eight more long years.
