384 SCIENCE PROGRESS 



destined to be sterile. There is still reason to hope that the 

 required synthesis will sooner or later be achieved. Life is pro- 

 bably a resultant of a number of forces — osmosis, diffusion, 

 accretion, nutrition and assimilation, heat and electricity acting, 

 it may be, upon certain salts ; the task of biology is to discover 

 how these forces act and the exact nature of the substances on 

 which they act. It would seem that this knowledge should be 

 obtained before the laws of heredity can be established upon 

 any but a risky basis, for as long as the process of life remains 

 undiscovered and the chemistry of living protoplasm is unknown, 

 it is impossible to arrive at any exact determination of the part 

 played by the reproductive cells in the transmission of character 

 from parent to offspring. Some useful information may, no 

 doubt, be obtained by a careful study of the effects of gametic 

 action but there will always be disconcerting exceptions to any 

 general rules that are established on these effects in ignorance 

 of the causes which produce them. Moreover, if living proto- 

 plasm varies in its chemical composition from organism to 

 organism, general principles of heredity would not hold 

 good. If the exact composition of the gamete is not known 

 for each variety of plant and animal, it is impossible to pre- 

 ascertain the effects of the geographically varying environment 

 upon it. 



If we do not know the exact effect of food substances 

 upon the growing protoplasm, we are again unable to account 

 for departures from a normality established on a far too wide 

 generalisation. For these reasons the laws of heredity cannot 

 be definitely established until the analysis of living protoplasm 

 has been performed and until the true nature of its reactions 

 with the outer world has been determined. 



This is the work of biology. The period of surmise and 

 generalisation from incomplete data is over. The biologists 

 must look to chemistry and to physics for the explanation 

 of the life phenomenon. Fortunately the laboratories are 

 active and we may hope for great elucidations in a not far 

 distant future. That life originally sprang from the inanimate 

 is hardly doubtful. That there is no fundamental difference 

 between the inorganic and the organic is proved by the fact that 

 a large number of substances long held to be unreproducible 

 in the laboratory have been there reproduced. It seems that 

 the inanimate must, if there were derivation at all, have given 



