Physiologie der Zellen, Gewebe und Organe. 59 



der Zeit darstellt, ohne Temperatur, Ernährung usw. zu berücksichtigen, läßt 

 keinen Schluß gegen die Theorie zu; chemische Reaktionsgeschwindigkeiten sind 

 ja auch nur isotherm konstant. Eine Übereinstimmung zwischen theoretischer 

 und empirischer Wachstumskurve ist nur dann zu erwarten, wenn Mittelwerte 

 aus so großem Material vorliegen, daß die zufälligen individuellen Fluktuationen, 

 welche durch die äußeren Bedingungen hervorgerufen werden, sich gegenseitig 

 aufheben und nicht in die Rechnung eingehen. Koehler (z. Z. Neapel). 



152) Livingston, B. E. (Johns Hopkins University), Adaptation in the living 

 and non-living. In: Amer. Natural, Bd. 47, S. 72 — 82, 1913. 



The author finds somewhat startling the fact that biology in the only science 

 which deals conspicuously with the idea of adaptation. He regards adaptations 

 as 'characteristics, properties or qualities attributable to natural objects', and 

 believes that, since the sciences of the non-living find no use for the conception 

 of adaptation, it will also pass out of biology when that science has reached more 

 maturity. The fact that pumice stone can float and is therefore 'adapted' for 

 transport by water, is of the same order of significance as any animal or plant 

 adaptation only the latter cannot be (at present) explained in terms of matter and 

 energy while the former can. The writer looks forward to the time when all 

 the sciences will deal only with matter and energy. Gates (London). 



153) Parker, G. H. (Harvard University), Adaptation in animal reactions. 

 In: Amer. Natural., Bd. 47, S. 83—89, 1913. 



The writer points out that adaptations in animals are not only essen tially 

 associated with the activities of organisms, but are conditioned by continuity 

 of those activities. An inorganic body may be resolved into its elements and re- 

 combined again, but an organism having undergone such a resolution is annihi- 

 lated. Life is a condition of continuous activity, and all reactions are to be con- 

 sidered adaptive which make for a continuance of life. Probably only a fraction 

 of the animal responses are really adaptive. Many favourable responses are not 

 necessarily adaptations. Animals have a wide latitude of behaviour consistent 

 ^\'ith the continuation of life, and the majori ty of animal reactions are probably 

 neither conspicuously advantageous nor disadvantageous to the life of the in- 

 dividual, for the environment permits of a generous variety of reactions under 

 given circumstances. 



On the other hand, while "the details of animal reactions are in the main 

 free from adaptive restraint", yet "the main outlines of animal reactions are 

 adaptive". Some adaptations appear to be of a kind which could not possibly 

 have originated through natural selection. The diversity of reactions depends 

 chiefly upon the momentarily fluctuating condition of the animal. To assume an 

 entelechy or "something like intelligence" as an explanation of animal behaviour 

 is arguing in a circle, for intelligence is merely our own most highly developed 

 means of adaptation. Gates (London). 



154) Mathews, A. P. (University of Chicago), Adaptation from the point 

 of view of the physiologist. In: Amer. Natural., Bd. 47, S. 90 — 104, 1913. 



This paper considers the questions of evolution and adaptation from a phy- 

 siological standpoint. Adaptation in the sense that a bird's body is fitted for 

 flight, is a physiological truism. Among the most difficult problems of evolu- 

 tion are (1) the phenomena of parallel evolution, (2) orthogenetic Variation, and 



