Page:Popular Science Monthly Volume 78.djvu/611

Rh be shown indirectly through analogical deductions. The cases of the museum are located in the entrance hall of the main building and in the adjoining front corridor. Most of the specimens are preserved in fluid, for only a few of the birds and mammals are stuffed and but a minority of the echinoderms and crustaceans are dried. The insects, hermetically sealed in shallow, glass covered cases, represent the influence of temperature upon lepidoptera, of protective resemblance and mimicry, of the series of moultings, of normal growth and growth as influenced by external factors and processes of regeneration, from the egg to the imago. In all cases it is important to have the normal control form exhibited alongside of the experimentally produced variation.

Dr. Przibram publishes a complete list of the animals cultivated in the Vienna institution with important data for each species, concerning the kind of vivarium, or aquarium used, its dimensions and the number of individuals which may there live together, the food, natural habitat and other details, as well as the name of the investigator and publication dealing with each form. The bibliography of papers published by the workers in the institution and Dr. Przibram's summary of these investigations and others being prosecuted furnish an outline of the remarkable scientific productivity resulting from only eight years of research. Such institutions as this of Vienna will do much to solve the great problems of biology. The practise of medical asepsis has permitted operations upon all classes of organisms giving new and valuable data in the field of regeneration. Color has been experimentally investigated as to its nature, whether due to the pigment formation or to the activity of chromatophores, and its relation to light, food, moisture and other external factors as well as its correlation with the animal's vision. By means of the chemical methods of precipitation, agglutination and coagulation, species and hybrids have been tested and the degree of relationship between members of larger groups has been indicated. By the combination of methods of breeding, and subjecting organisms to the influence of changed factors of existence, the laws of heredity will be more clearly established, and the inheritance of functional adaptations acquired under definitely controlled conditions may be demonstrated. The nature of the organ-forming substances in the germ cells and their embryogenesis is being studied. Through physico-chemical methods the biocolloids have become better known and finally the great mystery, the synthesis of living matter itself, may be revealed.