BIOLOGIC BALANCE — McATEE 321 



Territories seems to depend upon the degree of intolerance animals 

 have for their own kind. When the bounds are overstepped, conflict 

 soon results and the trespasser, as a rule, retires to its own domain. 

 The result is that creatures are confined almost as by a fence, inside 

 of which they must comport themselves so as not to spoil their own liv- 

 ing. If they materially damage the range, it will then be lost to their 

 species for a time. With such a system in operation almost everywhere, 

 it is apparent why natural balance usually prevails, and why if dis- 

 turbed it tends to return to equilibrium. Unbalance automatically 

 brings correction. 



Balance results from equalization of opposed forces, and in nature 

 these may be conceived of as a tendency for life to remain localized 

 and hold its place, offset by another under which it spreads and fills 

 any unoccupied habitat. The former leads to the holding of territory, 

 the latter to pioneering, and as a result of their interweaving, the woof 

 of life always pretty well fits the warp of environment. This is cer- 

 tainly balance. 



The web is woven only as life is sustained by air, soil, water, and 

 other life. In the realm of sustenance also, balancing factors prevail. 

 Where there is food, something will come to feed on it. If feeding goes 

 too far, the feeders must retreat. Under natural conditions consump- 

 tion is more or less in proportion to the supply and does not materially 

 encroach upon it. That is balance. 



Where encroacliment is noticed, it may usually be traced to some un- 

 natural condition produced by man. That is unbalance. Wherever 

 there is unbalance, nature seeks to correct it. Balance, if not always 

 evident, may be said to be ever imminent. 



When, regardless of change, a working balance becomes established, 

 it may be at a new level, and whether on that level it is advantageous 

 or not to man depends greatly on what man has done. If, for 

 instance, he has practiced clean farming to the extent that there is 

 little nesting cover for birds, there will, nevertheless, remain suffi- 

 cient cover for insects and they will increase. Their own internal wars 

 will produce some sort of balance, but it will be at a higher level — 

 there will be more insect mouths to feed. The farmer will have given 

 aid and comfort to the enemy. If he allows the fertility of the soil 

 to fall, as by uncontrolled erosion of the loam, the inhospitable sub- 

 soil will support fewer and less desirable plants. Vegetation will do 

 its best to reoccupy the land, but for a period the plant cover will be 

 sparse and weedy and will support little animal life of value to the 

 farm. The web of life is stretched thin to cover a barren place. 

 There may be balance but it will be at a low^er level than before. If 

 destructive influences cease, conditions will unprove slowly under 

 nature's management, though more rapidly under man's, if he will 



