THE STUDY OF HEREDITY 329 



themselves and like each other, than like any other kind of cell. 

 It can easily be demonstrated that there is no such thing as 

 absence of variation in any living organisms ; therefore, why 

 trouble to evolve hypotheses which are quite unnecessary ? 



I turn to Prof. Hartog and find that he attributes the origin 

 of variation to the inheritance of acquired characters. But I 

 find also that he has realised that the inheritance of mutilations 

 cannot occur, for " any tendency to transmit such deficiencies 

 would in course of time result in a generation of formless 

 imperfections that must needs be eliminated by natural selec- 

 tion." It is therefore evident that he believes that, if the tendency 

 to inherit particular acquirements made through the action of the 

 environment be injurious, the tendency will disappear. But a 

 very large proportion of the effects of every environment is 

 injurious to the organism. Certainly we find that the organism 

 has, as a rule, the power of reacting to these injurious factors 

 and surviving in spite of them ; but they must always do some 

 harm to the individual, as in the case of the children described 

 by Galton, 1 who invariably showed an arrest of growth during 

 even slight illnesses. We have ample material in the innate 

 variability of living matter without assuming the transmission 

 of the effect of the environment from parent to offspring; the 

 advantages of germ cells which do not transmit such acquire- 

 ments are obviously so great that they must have come under 

 the action of selection and any tendency to transmit acquirements 

 been eliminated. Prof. Hartog frequently expresses his dis- 

 approval of unnecessary assumptions, theories, and hypotheses. 

 I entirely agree with him, and as the fact that cells never 

 produce other cells exactly like themselves or like each other 

 seems ample to account for every diverse organism that exists 

 or has existed, I think his theory " falls under the ever trenchant 

 blade of Occam's razor." 



Of the whole stock of characters present in an individual 

 then, the great bulk have been derived from remote ancestors. 

 This stock is constantly being varied by what are comparatively 

 small additions and subtractions. Some of these are variations 

 of the individual organisms : its private property, so to speak. 

 They may be transmitted with increases or diminutions to the 

 offspring. Thus it becomes evident that a number of these 

 minor characters are inherited from near ancestors. Besides 



1 Inquiries into Human Faculty. 



