174 Review of Darwin’s Theory on the Origin of Species, 
eight orders, which showed how much these plants differed from each 
other. So it is with the plants and insects on small and uniform isles; 
and so in small ponds of fresh water. Farmers find that they can raise most 
a rotation of plants belonging to the most different orders; mi 
ture follows what may be called a simultaneous rotation. he 
animals and plants which live close round any small piece of ground, 
could live on it (supposing it not to be in any way peculiar in its natu), 
and may be said to be striving to the utmost to live there; but, it is seen, 
that where they come into the closest competition with each other, the 
advantages of diversification of structure, with the accompanying difier- 
ences of habit and constitution, determine that the inhabitants, which 
thus jostle each other most closely, shall as a general rule, belong! 
what we call different genera and orders.”—p. 114. 
The abundance of some forms, the rarity and final extinchon 
of many others, and the consequent divergence of character or 
increase of difference among the surviving representatives a 
other consequences. As favored forms inerease, the less fav 
must diminish in number, for there is not room for all; and the 
slightest advantage, at first probably inappreciable to human 
observation, must decide which shall prevail and which must 
perish, or be driven to another and for it more favorable locality. 
We cannot do justice to the interesting chapter upon natu . 
selection by separated extracts. The following must serve 
show how the principle is supposed to work. 
conditions of 
oC organization, 
and I think this cannot be disputed ; if there be, ewing to the pnt 
Sea eogepate 
asevere struggle for life, and this certainly cannot be disputed far 
| organie ° ing 
g an infinite 
sake of brevity, Natural Selection.”—pp. , 127. : s, 1 
“Tn order é make it clear how, aot believe, natural selection ee 
must beg permission to give one or two imaginary illustrations, 
take the case of a wolf, which preys on various animals, mee 
y craft, some by strength, and some by fleetness; and let jn the 
that the fleetest prey, a deer for instance, had from rib nom 
country increased in numbers, or that other prey had dee pressed OF 
n the wo 
