In the comprehensive text-book of physiological chemistry by R. Neumeister, the mechanical standpoint seemed to be adhered to as the ideal. But the same writer forsakes it entirely, and disputes it energetically in his most recent work, “Betrachtungen über das Wesen der Lebenserscheinungen”(84) (“Considerations as to the Nature of Vital Phenomena”). He passes over all the larger problems, such as those of development, inheritance, regeneration, and confines himself in the main to the physiological functions of protoplasm, especially to those of the absorption of food and metabolism. And he shows, by means of illustrations, in part Bunge’s, in part his own, and in close sympathy with Wundt’s views, that even these vital phenomena cannot possibly be explained in terms of chemical affinity, physical osmosis, and the like. In processes of selection (such as, for instance, the excretion of urea and the retention of sugar in the blood), the “aim is obvious, but the causes cannot be recognised.” Psychical processes play a certain part in the functions of protoplasm in the form of qualitative and quantitative sensitiveness. All the mechanical processes in living organisms are initiated and directed by psychical processes. Physical, chemical and mechanical laws are perfectly valid, but they are not absolutely dominant. Living matter is to be defined as “a unique chemical system, the molecules of which, by their peculiar reciprocal action, give rise to psychical and material processes in such a way that the processes of the one kind are always causally conditioned and started by those of the other kind.” The psychical phenomena he regards as transcendental, supernatural, “mystical,” yet unquestionably also subject to a strict causal nexus, although the causality must remain for ever concealed. Starting from this basis, he analyses and rejects the explanations which have been offered in terms of the analogy of ferments, enzymes, or catalytic processes. In particular, he disputes Ostwald’s “Energismus” and Verworn’s Biogen hypothesis.(85)