vious vague notions of the development of animals by exact accounts of the cell-origin of different organs of the body. Others have studied the abilities of mutilated animals to reproduce the parts lost and the conditions and limitations of such regeneration. Such studies have greatly broadened our views of the nature of animal tissues. Others have investigated the results of artificial conditions on the development of animals, especially in the earliest stages. For instance, from eggs broken into pieces there have been developed twins, triplets and monsters of various sorts. Such experiments as these are producing data concerning the very fundaments of living matter and are leading biology beyond the mere description of animal structures and functions towards an insight into the elementary principles of development. Among the numerous researches, some seventy in all, which are being carried on at Woods Holl this summer, those of the most general interest are Prof. C. O. Whitman's study of hybrids and Prof. Jacques Loeb's study of artificial fertilization. Prof. Whitman has been breeding pigeons of a large number of species for several years, as a means of studying the phenomena of heredity shown in hybrid forms. More or less incidentally, he has discovered many notable facts about the instincts and habits of the birds and about various physiological functions connected with reproduction. Biologists everywhere are coming to realize the necessity of systematic and continuous study of families of animals through a number of generations. Prof. Whitman's is the most extensive of such studies in this country. The detailed results of Prof. Loeb's continuation of his experiments on the action of various salts on unfertilized eggs will naturally be awaited with great interest. We have already noticed his success in causing unfertilized eggs of the sea-urchin to develop into normal individuals as far as the pluteus stage. He has this year succeeded in producing artificial parthenogenesis not only in starfish (Asterias), but also in worms (Chaetopterus). Through a slight increase in the amount of K-ions in the sea-water, the eggs of the latter can be caused not only to throw out the polar bodies as Mead had already observed, but also to reach the Trochophore stage and swim about as actively as the larvae originating from fertilized eggs.
In the courses of instruction offered at Woods Holl there are two of more than ordinary interest. Professor Loeb's course in physiology departs from the traditional study of physiological functions in the frog and in some mammal, and offers instead experimental work on the simpler invertebrate forms. The phenomena of life are there presented in diagrammatic form, and are interpreted as far as possible in terms of physics and chemistry. The course in nature study, given this year for the first time, offers to students without technical training a chance to learn about animals and plants from specialists. It has shown clearly that the best science is popular, that really scientific work can be done without previous drill in terminology or technique. A novel feature of the course has been the systematic experimental study of the instincts and intelligent performances of animals. The method of offering to intelligent men and women, who wish to know about animal life, but have no time or need for special technical training or detailed anatomical work, a chance to get something better than mere book knowledge or haphazard personal observation, should be widely extended.
The laboratory of the Brooklyn Institute of Arts and Sciences, situated at Cold Spring Harbor, Long Island, is nearly as old as the Woods Holl Laboratory. Prof. C. B. Davenport, its director, is probably the most active worker in this country in the quantitative study of variation, and one of the leading lines of research at Cold Spring Harbor is now and will probably be for
