Gilbert Hilton Scribner

“ Regarding the earth, then, as at one time an intensely hot globe, totally destitute of organic life, one of the principal and indispensable conditions of rendering it habitable for plants and animals evidently would be the radiation into space of its excessive and destructive heat. The accomplishment of this, with the train of concurrent effects which would follow, or at least ever have followed the gradual reduction of temperature, is all that would be necessary to render the earth a suitable place for the maintenance of vegetal and animal life. ”

“ Is there anything in similarity of form, anatomy, structure, size, color, food, habits, habitat, longevity, modes of propagation, terms of gestation, and capacity for inter-breeding between certain flora and fauna of the Eastern Continents and the Western, which would suggest that many species and varieties so widely separated might have come originally from the same locality and ancestry? Are plants and animals always improved, developed, and rendered prolific more by being moved one way than another? ”

“ A second great truth taught by examining the methods of these movements and studying the causes of this ceaseless tramp of organic life is, that certain essential elements of the environment itself are usually found to be traveling with or a little in advance of the migratory species. In other words, the rainfall and isothermal lines, the climatic and other conditions of life, are constantly and slowly changing relative to the locality, but moving in fact. ”

“ The individuals may be rooted and stationary, but the tribe is traveling, constantly leaving old fields and surroundings and as constantly arriving in new ones, sometimes crowded out, sometimes starved out, and sometimes invited out, but always moving—moving on to a new environment, better suited, taking all things into consideration, to satisfy the pressing needs of, and to develop and raise in the scale of being, both the individual and the species. ”

“ It is not at all necessary for the purposes of the present inquiry to examine the so-called nebular theory, nor even to ask when or how this globe became so heated, nor to what extent it has now become cooled, nor need we inquire whether the earth is now but a molten mass covered with a comparatively thin crust, or has cooled and hardened to its very center. ”

“ As there are no plants and no animals, with the exception of man, and possibly his companion the dog, and his pest the rat, that can thrive in most latitudes where any life is possible, so it is very evident that plants and animals, as we now see them, could not have made their advent upon the earth universally or simultaneously. ”

“ It is important, however, to have it understood at the outset that the facts and considerations here presented are addressed to those, and those only, who have reached and adopted the conclusion that this globe, at some time in the process of its formation and development, passed through a fiery ordeal, that the primary rocks are of igneous formation, and that there are many other existing conditions and obvious facts which can not well be accounted for except upon the hypothesis that the whole earth was once a molten mass. ”

“ All kinds of plants and animals which have remained in one locality until they have lost the means of movement, which can not or will not travel, must sooner or later first degenerate and then be exterminated. For instance, a rain-belt or an area of dew-fall veers slowly but permanently from the north to the south; an arid soil is made fertile, and a fertile soil is left arid; the grass and flowering plants in endless variety move with the dew or the rain-belt; the deer follow the grass, and the wolves follow the deer ”

“ The methods and means by which the seeds of plants are carried and deposited in new localities, the agency of insects, birds, and other animals in their distribution, no less than their own ingenious contrivances for floating with the wind and tide, and for catching on to every moving object, all have been carefully observed and faithfully chronicled. ”

“ It has been frequently observed that certain species, occupying some particular territory now, have at some recent time in the past been enabled by such changes to crowd out other occupants of the same territory, and in turn will be undoubtedly, by similar changes and means, crowded out themselves. ”

“ But this sun-heat, this offset to radiation, has not been received by all parts of the earth equally. The equatorial belt, or torrid zone, has always received the most per square foot, or in proportion to its area. The two intermediate or temperate zones have received the next largest amount per square foot, or in proportion to their area; while the polar or frigid zones have received the least per square foot, or in proportion to their area. ”

“ THE subject of the distribution of plants and animals has for a long time engaged the attention of many able, persistent, and discriminating investigators. Much time and effort have been expended in simply observing and describing the various means by which they get about from place to place. ”

“ It is not claimed that these views have been proved to be true inductively, but there are certain facts and phenomena pointing directly to definite conclusions hereinafter stated which I am sure every one holding and believing that the earth was at one time a molten mass will find it easier and more reasonable to admit than to deny. ”

“ This condition of things would indicate the possibility at least that life upon the earth had in the main commenced in some favored area, and traveled thence far and wide over the surface of the globe, driven out by changes of environment, lessening in effect the favorable conditions of its development in the place of its beginning, and ever beckoned on by more favorable conditions in adjacent districts. ”