II. Observations on the physiology and histology of Convoluta schultzii

Chlorophylloid green colouring matters are known to exist in the tissues of a not inconsiderable number of animals belonging to very various invertebrate groups—Protozoa, Porifera, Cœlenterata, Vermes, and even Crustacea; but all information as to the function of chlorophyll in the animal organism is wanting. Wöhler, it is true, found many years ago thatChlamydomonas, Euglena &c., evolve oxygen in sunlight, and Schmidt prepared fromEuglena viridis a body isomeric with starch, though of widely different properties, his paramylon; but these facts seemed as much to point towards the algoid nature of these long disputed organisms as to warrant our supposing a more or less vegetable mode of life in animals so well organised, and so evidently carnivorous as Coelenterates and Turbellarians, especially as the only recorded experiment, that of Max Schultze onVortex viridis, yielded atotally negative result. Some such hypothesis, however, can hardly help recurring to the observer of the light-seeking habit ofHydra viridis .