in the case of certain snakes, placed under the skin bony representatives of the extremities, the movements of those animals being by the use of the ribs, and feet never being wanted?
We may also turn to the vegetable world, and there we find rudimentary organs, excesses and deficiences of development. As Treviranus says, adaptation to the surrounding world may be shaped either by gradual development or by degeneration, which is equally effective. The same organ may be expanded into a compound leaf, or degenerated into a scale. Development can turn a reptile into a bird; degeneration can turn it into a serpent. Any flower may be regarded as a transformed branch—that which might have evolved into a leaf turns indifferently, as circumstances may direct, into a sepal, a petal, or a stamen.
Rudimentary organs come into existence as part of a general plan. They are the manifestation of heredity in the type of life of the animals or plants in which they occur. They prove that the form has been developing, not teleologically, or for a purpose, but in obedience to law.
Now I have answered, and I know how imperfectly, your question, "How does the hypothesis of evolution force itself upon the student of modern science?" by relating how it has forced itself upon me, for my life has been spent in such studies, and it is by meditating on facts like those I have here exposed that this hypothesis now stands before me as one of the verities of Nature.
In doing this I have opened before you a page of the book of Nature—that book which dates from eternity and embraces infinitude. It reveals millions of suns and worlds of surpassing glory. Among its most insignificant pages are the vast rock-strata of the earth. We have been looking at some of them. No Council of Laodicea, no Tridentine Council, is wanted to indorse its authenticity, nothing to assure us that it has never been tampered with by any guild of men, to perpetuate their influence, secure their profits, or otherwise promote their ends.
Then it is for us to study it as best we may, and to obey its guidance, no matter whither it may lead us.
And this brings me face to face with the third division of my subject. I have spoken of the origin and the progress of the hypothesis of evolution, and should now consider the consequences of accepting it. Here it is only a word or two that time permits, and very few words must suffice. I must bear in mind that it is the consequences from your point of view to which I must allude. Should I speak of the manner in which scientific thought is affected, should I dwell on the influence this theory is exerting on general knowledge, I should be carried altogether beyond the limits of the present hour.
The consequences! What are they, then, to you? Nobler views
