THE WORM STRIVING TO BE MAN 
of the earth, and in different geological periods, no 
doubt checked it when it occurred, But the tide as a 
whole must have steadily risen, because the progres- 
sion from lower to higher forms has gone steadily 
forward. The lower forms have come along; Nature 
has left nothing behind. The radiates, the articu- 
lates, the mollusca, are still with us, but in the 
midst of these the higher and higher forms have 
been constantly appearing. The great biological 
tree has got its growth. Many branches and twigs 
have died and dropped off, and many more will do 
so, are doing so before our eyes, but I cannot help 
doubting that any new branches of importance are 
yet to appear — any new families or orders of birds, 
or fishes, or reptiles, or mammals. The horse, the 
stag, the sheep, the dog, the cat, as we know them, 
are doubtless the end of the series. One arrives at 
this conclusion upon general principles. Life as a 
whole must run its course or reach its high-water 
mark, the same as life in its particular phases. Man 
has arrived and has universal dominion; all things 
are put under his feet. The destiny of life upon the 
globe is henceforth largely in his hands. Not even 
he can avert the final cosmic catastrophe which 
physicists foresee, and which, according to Pro- 
fessor Lowell, the beings upon Mars are now strug- 
gling to ward off. 
Man has taken his chances in the clash of forces 
of the physical universe. No favor has been shown 
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