The above brief references to the research work of the subject of this sketch would be too incomplete did we omit mention of his papers upon that very interesting and extremely ancient inhabitant of the Chesapeake, the Lingula, or of the beautifully illustrated memoir of the National Academy of Sciences, describing the crania of the Lucayan Indians, an unfortunate race of gentle beings discovered by the Spaniards and treated as part of the live stock of the New World and soon annihilated, leaving but a few bones, and, as Professor Brooks tells us, our familiar and pleasant word "hammocks," as evidences of their having been. Coming to maturity in the period of general acceptance of the Darwinian hypothesis of organic evolution, Professor Brooks was naturally deeply influenced, and no one who has read his works can doubt his allegiance to natural selection as a powerful factor in the formation of the present order of living things. In the American Naturalist for 1877 he published the first outlines of a provisional hypothesis of pangenesis that sought to "combine the hypotheses of Owen, Spencer, and Darwin in such a way as to escape the objections to which each is in itself liable, and at the same time to retain all that renders them valuable." In 1883 the same hypothesis--that variations are perpetuated chiefly through the male line by special gemmules, and that the female is essentially conservative--was elaborated in book form under the title of The Law of Heredity. Thenceforth, in intervals of research work, Professor Brooks has contributed to various periodicals, notably the Popular Science Monthly, such essays upon kindred topics as spontaneously arose in his mind in connection with current work here and abroad. Some of these of a general philosophical interest have been incorporated with lectures, originally given to students in Baltimore, as The Foundations of Zoölogy, brought out this year by the Macmillan Company as Volume V of the Columbia University Biological Series. This, it will be noted, is dedicated "To Hobart College, where I learned to study, and, I hope, to profit by, but not blindly to follow, the writings of that great thinker on the principles of science, George Berkeley," and its keynote might be said to be difficult to hold, expressing the standpoint of one who says "The proof that there is no necessary antagonism between mechanical explanations of human life and belief in volition and duty and moral responsibility seems to me to be very simple and easy to understand."