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."
Though thus active in pushing forward the limit of fact and theory in the domain of pure science, Professor Brooks has not shirked the duty that falls to every member of society, but has labored earnestly to build a sound basis for immediate practical application of zoölogical research. In 1876 he organized a summer zoölogical laboratory for teachers and others in Cleveland, with the co-operation of two other young Clevelanders—A. H. Tuttle, now Professor of Biology in the University of Virginia, and I. B. Comstock, Professor of Geology in the University of Arizona.
Identifying himself with the interests of the community in which he had cast his lot, he interested himself in the establishment of such educational influences as that of a public aquarium, and it was through no fault of the sower that the seed laboriously sown fell upon stony ground. In the winter of 1880 he gave a course of lectures and of laboratory work for teachers in the schools of Baltimore.
Again, his early studies of the development of the oyster (for which he was awarded the medal of the Société d'Acclimatisation of Paris in 1883), his discovery that the American oyster could be reared like fish from artificially fertilized eggs, since he found it to have a different life history from its European fellow, led him to realize the greater possibilities that awaited our oyster industries when they should be based upon scientific fact. Living amid a population dependent to no small extent upon these industries, Professor Brooks threw himself with enthusiasm into the problem of warding off the ruin that comes to every enterprise expanding faster than its capital is replenished, and eagerly sought the means to magnify without deterioration so important a factor in the existence of the Commonwealth. As chairman of the Oyster Commission appointed by the General Assembly of Maryland in 1882, he drew up the long, detailed, and well-illustrated report, issued in 1884, which set forth the condition of the oyster beds in the Chesapeake Bay and their deterioration from overwork, and suggested a legislative remedy in the form of a bill designed to remove this industry from that primitive, barbaric stage in which our communal ownership of migrant birds and fish still remains, and to place it upon the secure basis of personal ownership underlying other live-stock business. But it is difficult to change the customs of centuries' standing, and prophets rarely see the fulfillment of their predictions. Many lectures and the issue of a popular book—The Oyster, 1891—were necessary labors assumed by Professor Brooks before the public mind was educated to some appreciation of the nature of the problem, and the fruits of his labors are yet to be matured and gathered.
But it is not so much by discovery of new facts or by aid to the community in which one may chance to live that a man exerts his best influence upon mankind; rather by his success in inspiring others to see whatever of good there may be in his point of view and method of attack upon old problems, that his followers may keep alive and enlarge what he stands for in the growth of civilization. As a teacher Professor Brooks has exerted a powerful influence by the stimulus of example in his whole-hearted devotion to research, by originality of suggestion, and by his clear intuition of the essential factors in morphological problems. Convinced that naturalists, like poets, are born and not made—or, if so, then self-made—his teaching has been free from that too easily acquired hallucination that the forcible introduction of facts, and frequent extraction of words by means of examination, are a possible means to the making of zoölogists, or what you will to order, to be ticketed and branded as such after a fixed term of the above process. Those who are strong enough to grow in the open have found in him a genial sunshine, but those needing hothouse forcing have sometimes missed, perhaps, the care necessary to bring them to a marketable state.
Many who have followed his lectures will recall the clearness and simplicity with which complex and puzzling questions were presented to their minds; the skull of the bony fish soon lost its terrors, while the homologies of the limb bones were brought to the mind in a graphic way, sure to leave a deep impression. Directness and lucidity, with freedom from investment of unessentials, are characteristics of his teaching and prominent features in his too little known Handbook of Marine Zoölogy, which, despite technical faults, was so original and honest, so free from closet natural history, that it marked an era in the advance of biological instruction. It was a direct appeal to the concrete study of living animals at a time when zoölogy for students was still the learning of text-books, and text-books were too often in spirit but modernizations of Pliny or of Aldrovandus.
It is this removal of the impeding paraphernalia of custom-bound authority, and a direct, childlike communion with Nature in search of truth by one's unaided labor, that this man has to offer to those who come under his sway as teacher; with what success will be evident from the work of those who recently united to honor his fiftieth birthday with a portrait that might recall him to them as he taught them, and from the work of those who, in coming years, will enjoy the privilege of contact with his genius and be led to "seek admission to the temple of natural knowledge naked and not ashamed, like little children."