In a confined or isolated area, if not very large, the organic and inorganic conditions of life will generally be in a great degree uniform; so that natural selection will tend to modify all the individuals of a varying species throughout the area in the same manner in relation to the same conditions.
But we may thus greatly deceive ourselves, for to ascertain whether a small isolated area, or a large open area like a continent, has been most favourable for the production of new organic forms, we ought to make the comparison within equal times; and this we are incapable of doing.
All fresh-water basins, taken together, make a small area compared with that of the sea or of the land; and, consequently, the competition between fresh-water productions will have been less severe than elsewhere; new forms will have been more slowly formed, and old forms more slowly exterminated.
For the area will first have existed as a continent, and the inhabitants, at this period numerous in individuals and kinds, will have been subjected to very severe competition.
But as from the high geometrical powers of increase of all organic beings, each area is already fully stocked with inhabitants, it follows that as each selected and favoured form increases in number, so will the less favoured forms decrease and become rare.
Nor is this strange, for Pellucidar, in its land area
, is immense, while the human race there is very young and consequently far from numerous.
Near the head of the lagoon I was much surprised to find a wide area
, considerably more than a mile square, covered with a forest of delicately branching corals, which, though standing upright, were all dead and rotten.
It was not long, however, before the restless savages were heard beating the brush, and gradually approaching the inner edge of that dense border of young chestnuts which encircled the little area.
Curbing his impatience, he again looked out upon the area, and awaited the result in silence.
Then they drew warily back, keeping their eyes riveted on the ruin, as if they expected to see the apparitions of the dead issue from its silent walls, until, having reached the boundary of the area, they moved slowly into the thicket and disappeared.
Targets are areas
into which the ball should be served.
Information is just as critical a resource for people, businesses, and communities in rural areas
as it is for those in urban areas