"The world has arisen in some way or another. How it originated is the great question, and Darwin's theory, like all other attempts to explain the origin of life, is thus far merely conjectural. I believe he has not even made the best conjecture possible in the present state of our knowledge."

“The facts will eventually test all our theories, and they form, after all, the only impartial jury to which we can appeal.”

“The time has come when scientific truth must cease to be the property of the few, when it must be woven into the common life of the world.”

“Foldings of the earth's crust, low hills, extensive plains, mountain-chains and narrow valleys, broad table-lands and wide valleys, local chimneys or volcanoes, river-beds, lake-basins, inland seas,—such are some of the phenomena which, disconnected as they seem at first glance, have nevertheless been brought under certain principles, and explained according to definite physical laws.”

“The eye of the trilobite tells us that the sun shone on the old beach where he lived; for there is nothing in nature without a purpose, and when so complicated an organ was made to receive light, there must have been light to enter it.”

“The crust of our earth is a great cemetery, where the rocks are tombstones on which the buried dead have written their own epitaphs.”

“But whatever its defects, the classification of Linnæus was the first attempt at grouping animals together according to certain common structural characters.”