plishing a remarkable amount of work in science, for he devoted his Bummers to study upon the seashore at a time when the waters of many a now polluted harbor were pure, so that he discovered many new and remarkable marine animals in the neighborhood of Boston, where now nearly all aquatic life has disappeared. He produced eighteen publications during this period, the most notable being his illustrated catalogue of the "North American Acalephæ," containing descriptions of many new and interesting forms of medusæ from the Pacific and Atlantic coasts, and illustrated by 360 figures drawn from life by his own hand. It is but a just tribute to his thoroughness as a collector and observer to say that some of these medusae have never again been seen since he discovered them off the New England coast fifty years ago.
Another interesting paper of this period is his "Embryology of the Starfish" of 66 pages illustrated by 8 plates containing 113 figures beautifully drawn from life by the author; and yet another paper is upon the young stages of annelid worms in which he shows that in past ages adult worms were often provided with very large bristles, and that the young of existing marine worms still have such structures. At this time also he wrote much upon echinoderms, and made substantial progress upon that great work of his early manhood, the "Revision of the Echini," which finally appeared in four parts between 1872-74 and consists of 762 quarto pages of text and 94 plates; composed of drawings and photographs made by the author. This work caused his father keen delight, for he foresaw that it portended a distinguished career in science to his gifted son. It won the Walker prize of $1,000 from the Boston Society of Natural History, and brought to its young author an international reputation.
In 1866 he was elected to membership in the National Academy of Sciences, which at that time recruited itself from the active young workers of the country. He was president of the academy from 1901 to 1907, and its foreign secretary from 1891 to 1901 and from 1908 until his death in 1910. He bequeathed $50,000 to the academy. He was also deeply interested in the American Academy of Arts and Sciences and served as its president, gave large sums to it and left it $50,000 after his death. These two academies were the only scientific associations of America in which he took any active interest. Between 1860 and 1866 he laid the foundation for all that he was to achieve in science, with the exception of his elaborate explorations of coral reefs, and, with this exception, all of the subjects which were to engross his attention in future years were then engaging his active interest. He never departed from the thought and method of these early days, and he always spoke of them with loving remembrance as "the good old days"—their influence upon his scientific career was paramount. For example, he never adopted the methods of the his-
