ABSTRACT
In a recent paper (Gray, 1928 a) the progressive loss of activity of a suspension of Echinus sperm was considered from two points of view; firstly, as a process of spontaneous and irreversible depletion of available energy and secondly, as a process of auto-intoxication whereby the products of activity inhibit the essential reactions of life. Both of these hypotheses led to a quantitative relationship between the total oxygen absorbed by a suspension and the period of time which had elapsed since the beginning of active life. This relationship was, in both cases, in harmony with that recorded by experiment, so that it is only possible to judge the relative merits of the two hypotheses by the intrinsic probability of the underlying assumptions, or by the provision of more specific data. An attempt to provide such data has proved detrimental to both theories.
The statistical analysis here given is not dependent on the precise nature of the distribution curve employed. The particular curve adopted was suggested to me by Mr G. U. Yule to whom I am indebted for many fruitful suggestions ; to Prof. A. V. Hill I also owe my thanks for much stimulating criticism.