The symposium on the ‘Plant Geography of North American,’ to be given at the coming meeting of the American Association for the Advancement of Science, will do much to systematize investigations of this character and broaden the method of treatment accorded the subject in the future. _BIOLOGY._ The ‘Biological Lectures from the Marine Laboratory of Woods Holl, 1899,’ make up a volume of about three hundred pages which represent fairly the present tendencies of biological investigation in this country. The most striking things about the lectures are the wide range of topics which they treat, and the first-hand quality of the subject matter in each case. This is most clearly seen by a careful reading of the text, but a mere enumeration of a few of the sixteen titles and lectures makes it fairly obvious. Thus, D. P. Penhallow writes on ‘The Nature of the Evidence Exhibited by Fossil Plants, and its bearing upon our Knowledge of the History of Plant Life;’ D. T. MacDougal writes on the ‘Significance of Mycorrhizas,’ Edward Thorndike on ‘Instinct,’ Herbert S. Jennings on ‘The Behavior of Unicellular Organisms,’ Alpheus Hyatt on ‘Some Governing Factors usually neglected in Biological Investigations,’ T. H. Morgan on ‘Regeneration,’ C. B. Davenport on ‘The Aims of the Quantitative Study of Variation,’ Jacques Loeb on ‘The Nature of the Process of Fertilization.’ To the professed scientist these lectures will furnish expert opinion on certain important topics; the general reader will find in them a presentation not too technical or detailed. Professor Loeb’s lecture, for example, is for such readers the best account yet given of his experiments in artificial fertilization. The range and originality which characterize these lectures are really characteristic of the general work and spirit of the Woods Holl Laboratory. Few people realize the amount of research work which is done there from summer to summer. Yet last year there were seventy-one investigators there. Moreover, these represent a superior selection from among the instructors and students of the various colleges. It is a symptom of a healthy, vigorous condition in biological science that the best workers of the country are glad to devote their vacation season to research, and it is highly creditable to the Woods Holl management that it offers them such attractive facilities. Similar summer laboratories are now being established in other parts of the country, and are to be reckoned with as very important factors in the progress of biology. _CYTOLOGY._