for light, ventilation, and cleansing. All the ordinary laboratory rooms are supplied with aquarium equipment. The two chief designs of the laboratory may be categorically expressed: (1) to provide material for the extension of physiological investigation to the whole animal kingdom and even to the plant world; (2) to provide opportunity for studying the effect of all environmental conditions singly upon living forms. The importance of these is manifest. Physiologists have been too much inclined to learn their lessons from man alone, or from man and a few of the higher mammals. Certain processes, however, absent or obscure in man, are present or better defined in some other forms. Phenomena vary with types: one is at its best in one species, another in another; a wide range, therefore, of forms is necessary. In studying the effects of environment it is desirable, so far as possible, to isolate the elements of which it is composed. It is an easy matter to attribute an effect to the wrong factor in the surroundings. The Physiological Laboratory is in a sense an expression of its head, Prof. Jacques Loeb. Dr. Loeb was trained in the most important laboratories of Europe, and his investigations therein were of extreme interest. His study of heliotropism demonstrated that the tendency of plants to turn sunward was the same thing as the impulse which drives the moth to the flame; that there is no more psychical activity in the latter than in the former. His later investigations into the mechanism of geotropism, or the tendency to turn or grow toward the earth, and other kindred phenomena, amplified and further illustrated these conclusions. His curious investigation into heteromorphosis—substitution of one organ by another, transformation of one organ into another—was really an outgrowth of these studies. The importance of the results of the whole series is illustrated in a recent article by Dr. Loeb upon egg structure and the heredity of instincts. Recognition that much of what has heretofore been considered psychical in instinct is merely the necessary result of chemical actions and the mechanical operations produced by them, given external combinations of conditions being present, greatly simplifies the conception of egg structure, and relieves us of some of the embarrassingly complicated conceptions in certain of Weismann's later theories.
The Botanical Laboratory, under Prof. Coulter's direct supervision, is the fourth of this striking cluster of buildings. The most notable feature is the greenhouse in the roof. From below it appears small, but it probably measures something like seventy by thirty feet. It serves two excellent ends: (a) it supplies material at every stage of growth for laboratory use; (b) it furnishes all kinds of conditions for experimentation. The arrangements for control in temperature and moisture are nearly perfect.
