THE WORM STRIVING TO BE MAN 
him. The mollusk remains, but some impulse went 
out from the mollusk that begat the fish. The fish 
remains, but some impulse went out from the fish 
that begat the amphibian. The amphibian remains, 
but some impulse went out from the amphibian that 
begat the reptile. The reptile remains,: but some 
impulse went out from the reptile that begat the 
mammal; and soon up to man. Man must have had 
a specific line of descent. One golden thread must 
connect him with the lowest forms of life., And the 
wonder is that this golden thread was never snapped 
or lost through all the terrible vicissitudes of the geo- 
logic ages. But I suppose it is just as great a wonder 
that the line of descent of the horse, or the sheep, or 
the dog, or the bird, was not snapped or lost. Some 
impulse or tendency was latent or potential in the 
first unicellular life that rested not till it eventuated 
in each of these higher forms. Did any terrestrial or 
celestial calamity endanger the line of descent of 
any of the higher creatures? Was any form cut off 
in the world-wide crustal disturbances of the earth 
at the end of paleeozoic and mesozoic time, when so 
many forms of animal life appear to have been 
wiped out, that might in time have given birth to a 
kind unlike or superior to any now upon the earth? 
Species after species have become extinct, whole 
orders and families have gone out, often rather sud- 
denly. Why we know not. Why the line of man’s 
descent was not cut off, who knows? It is a vain 
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