THE IDEA which gives Agassiz his distinct individuality as a thinker belongs to the highest poetry of science. He suggests it in his essays on Classification by expressing his belief in the existence in every animal “of an immaterial principle similar to that which by its excellence and superior endowments places man so much above animals.” “The principle exists unquestionably,” he adds, “and whether it be called soul, reason, or instinct, it presents in the whole range of organized beings a series of phenomena closely linked together and upon it are based not only the higher manifestations of the mind, but the permanence of the specific differences which characterize every organism.”

  This is the logical antithesis of the Darwinian hypothesis against which Agassiz was one of the few great scientists of Darwin’s generation whose protest was unqualified. He made no concessions to it, declaring it inconceivable that any force of mere physical heredity supposable as innate in matter could transmit the life and the traits of one individual of a species to another.

  He was the son of a Swiss clergyman, and was born May 28th, 1807, in his father’s parish of Motier. Educated at Lausanne, Zurich, Heidelberg, and Munich, he took his degree in medicine only to abandon that profession for the scientific research to which he devoted his life. His greatest work was as a specialist in the study of ichthyology, and some of his most far-reaching generalizations on the governing laws of life in all its forms are directly suggested by his study of turtles. After such researches had made him one of the most famous men of Europe, he came to the United States in 1846 to deliver a series of lectures at the Lowell Institute. He held professorships at Harvard and in Charlestown. The museum of natural history at Cambridge is a monument of his American work. His “Contributions to the Natural History of the United States” are among the most interesting of his numerous publications, and the essays on Classification which they embody show a faculty of clear statement and succinct generalization, suggesting the best work of Aristotle. He died December 14th, 1873. One of his sayings should be forever memorable in America and in the world. Tempted with lucrative employment which would have called him away from his scientific work, he answered: “I have no time to make money.”