The Lake as a Microcosm. 87 
adjusted aquatic animal will, in time crowd out his poorly-adjusted competi- 
tors for food and for the various goods of life. Consequently we may believe 
that in the long run and as a general rule, those species which have survived, 
are those which have reached a fairly close adjustment in this particular. 
Two ideas are thus seen to be sufficient to explain the order evolved from 
this seeming chaos; the first that of a general community of interests among ° 
‘all classes of organic beings, and the second that of the beneficent power of 
natural selection which compels such adjustments of the rates of destruction 
and of multiplication of the various species as shall best promote this common 
interest. 
Have these facts and ideas derived from a study of our aquatic microcosm 
any general application on a higher plane. We have here an example of the 
triumphant beneficence of the laws of life applied to conditions seemingly the 
most unfavorable possible for any mutually helpful adjustment. In this lake, 
where competitions are fierce and continuous beyond any parallel in the worst 
periods of human history; where they take hold not on the goods of life, 
merely, but always upon life itself; where mercy and charity and sympathy 
and magnanimity and all the virtues are utterly unknown; where robbery and 
murder and the deadly tyranny of strength over weakness are the unvarying 
rule; where what we call wrong-doing is always triumphant, and what we call 
goodness would be immediately fatal to its possessor,—even here, out of these 
hard conditions, an order has been evolved which is the best conceivable with- 
out a total change in the conditions themselves; an equilibrium has been 
reached and is steadily maintained that actually accomplishes for all the par- 
ties involved the greatest good which the circumstances will at all permit. In 
a system where life is the universal good, but the destruction of life the well 
nigh universal occupation, an order has spontaneously risen which constantly 
tends to maintain life at the highest limit,— a limit far higher, in fact, with 
respect to both quality and quantity, than would be possible in the absence of 
this destructive conflict. Is there not, in this reflection, solid ground for a 
belief in the final beneficence of the laws of organic nature? If the system 
of life is such that a harmonious balance of conflicting interests has been 
reached where every element is either hostile or indifferent to every other, 
may we not trust much to the outcome where, as in human affairs, the spon- 
taneous adjustments of nature are aided by intelligent effort, by sympathy, and 
by self-sacrifice? 
