|SKETCH OF PROFESSOR HAECKEL.|
ERNST HEINRICH HAECKEL, Professor of Natural History in the University of Jena, and one of the most eminent of German biologists, was born at Potsdam, in Prussia, on the 16th of February, 1834, and is consequently now but forty years of age. In his childhood he was very fond of botany. He studied medicine and the natural sciences at Berlin and Würzburg, and graduated as doctor of medicine in Berlin in 1857. In Würzburg he studied anatomy and histology under Kölliker and Leydig, and in Berlin under Johannes Müller. He became the assistant of the eminent pathologist Virchow, and commenced medical practice in Berlin in 1858. He had made scientific excursions to the Mediterranean in 1854 and 1856 with Kölliker and Müller; and in 1859-'60 a fifteen months' residence in Italy, which he employed in zoological researches, became the turning-point in his career, and he withdrew from the practice of medicine, and became a professed zoologist. He went to Jena in 1861, and was made professor extraordinary in the university in 1862. In 1865 the university created a regular chair of zoology specially for him, and he began the formation there of a valuable museum. From that time his lectures, together with those of Gegenbaur on comparative anatomy, have given great reputation to the Jena school. Prof. Haeckel is said to have declined very advantageous appointments to other universities mainly because he would not be separated from his friend Gegenbaur. Prof. Haeckel early accepted the views of Mr. Darwin, and has become their leading expositor in Germany. He has, besides, greatly extended and strengthened the theory of organic development by his own researches. His biographer in the American Cyclopædia states that in 1863 "Darwinism" was generally looked upon with great disfavor in German scientific circles; and when, on September 19th of that year, Prof. Haeckel appeared before the convention of German physicians and naturalists held in Stettin, as the enthusiastic advocate of development doctrines, he stood almost alone, and thenceforth he determined to devote his life to their extension, establishment, and promulgation.
In 1866 he completed a work on the general morphology of organisms, in two volumes, which ranks as one of the landmarks of the science. In that work he propounded, as a fundamental biological law, "that the individual development of every organism, or the series of forms through which it passes from germ to complete form, repeats approximately the development of its race, or the series of forms through which its ancestors have passed. Moreover, all organic beings, hitherto, had been classified into the two kingdoms, animal and vegetable; but a number of creatures were found to present in exter-