You cannot do without one specialty. You must have some base-line to measure the work and attainments of others. For a general view of the subject, study the history of the sciences. Broad knowledge of all Nature has been the possession of no naturalist except Humboldt, and general relations constituted his specialty.

The long summer was over. For ages a tropical climate had prevailed over a great part of the earth, and animals whose home is now beneath the Equator roamed over the world from the far South to the very borders of the Arctics ... But their reign was over. A sudden intense winter, that was also to last for ages, fell upon our globe.

When chemists have brought their knowledge out of their special laboratories into the laboratory of the world, where chemical combinations are and have been through all time going on in such vast proportions,-when physicists study the laws of moisture, of clouds and storms, in past periods as well as in the present,-when, in short, geologists and zoologists are chemists and physicists, and vice versa,-then we shall learn more of the changes the world has undergone than is possible now that they are separately studied.

Facts are the words of God, and we may heap them together endlessly, but they will teach us little or nothing till we place them in their true relations, and recognize the thought that binds them together.

Embryology furnishes, also, the best measure of true affinities existing between animals.

The study of Nature is intercourse with the Highest Mind.

I may say that here, as in most cases where the operations of nature interfere with the designs of man, it is not by a direct intervention on our part that we may remedy the difficulties, but rather by a precise knowledge of their causes, which may enable us, if not to check, at least to avoid the evil consequences.