The amount of food for each species of course gives the extreme limit to which each can increase; but very frequently it is not the obtaining food, but the serving as prey to other animals, which determines the average numbers of a species.
Climate plays an important part in determining the average numbers of a species, and periodical seasons of extreme cold or drought, I believe to be the most effective of all checks.
When a species, owing to highly favourable circumstances, increases inordinately in numbers in a small tract, epidemics--at least, this seems generally to occur with our game animals--often ensue: and here we have a limiting check independent of the struggle for life.
On the other hand, in many cases, a large stock of individuals of the same species, relatively to the numbers of its enemies, is absolutely necessary for its preservation.
Number Thirteen turned in surprise at the cry, and sensing a new danger for her who lay in his arms, he set her gently upon the ground behind him and advanced to meet his assailant.
Number Thirteen did not understand the words that the other addressed to him but he interpreted the man's actions as menacing, not to himself, but to the creature he now considered his particular charge; and so he met the advancing man, more to keep him from the girl than to offer him bodily injury for he recognized him as one of the two who had greeted his first dawning consciousness.
Von Horn, possibly intentionally, misinterpreted the other's motive, and raising his bull whip struck Number Thirteen a vicious cut across the face, at the same time levelling his revolver point blank at the broad beast.
Number Thirteen knew nothing of the danger of firearms, but the noise had startled him and his experience with the stinging cut of the bull whip convinced him that this other was some sort of instrument of torture of which it would be as well to deprive his antagonist.
In this time we daily expected the arrival of the Indian army; and at length, one of my fellow prisoners, escaping from them, arrived, informing us that the enemy had an account of my departure, and postponed their expedition three weeks.--The Indians had spies out viewing our movements, and were greatly alarmed with our increase in number and fortifications.
We took from them three horses, and all their baggage; and being informed, by two of our number that went to their town, that the Indians had entirely evacuated it, we proceeded no further, and returned with all possible expedition to assist our garrison against the other party.
On the eighth, the Indian army arrived, being four hundred and forty-four in number, commanded by Capt.
It was now a critical period with us.--We were a small number in the garrison.--A powerful army before our walls, whose appearance proclaimed inevitable death, fearfully painted, and marking their footsteps with desolation.