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ape; or, in the other case, as a ramification of the same 
primitive stock as those apes. 
At the present moment, but one such process of physical 
causation has any evidence in its favour; or, in other words, 
there is but one hypothesis regarding the origin of species of 
animals in general which has any scientific existence-—that 
propounded by Mr. Darwin. For Lamarck, sagacious as 
many of his views were, mingled them with so much that 
was crude and even absurd, as to neutralize the benefit which 
his originality might have effected, had he been a more sober 
and cautious thinker; and though I have heard of the 
announcement of a formula touching “the ordained con- 
tinuous becoming of organic forms,” it is obvious that it is 
the first duty of a hypothesis to be intelligible, and that a 
qua-qua-versal proposition of this kind, which may be read 
backwards, or forwards, or sideways, with exactly the same 
amount of signification, does not really exist, though it may 
seem to do so. 
At the present moment, therefore, the question of the 
relation of man to the lower animals resolves itself, in the 
end, into the larger question of the tenability or untenability 
of Mr. Darwin’s views. But here we enter upon difficult 
ground, and it behoves us to define our exact position with 
the greatest care. 
It cannot be doubted, I think, that Mr. Darwin has satis- 
factorily proved that what he terms selection, or selective 
modification, must occur, and does occur, in nature; and he 
has also proved to superfluity that such selection is com- 
petent to produce forms as distinct, structurally, as some 
genera even are. If the animated world presented us with 
none but structural differences, I should have no hesitation 
in saying that Mr. Darwin had demonstrated the existence 
of a true physical cause, amply competent to account for the 
origin of living species, and of man among the rest. 
But, in addition to their structural distinctions, the species 
