How Darwinism Stands To-Day 379 



holism on the part of a strong parent may prejudice the off- 

 spring by provoking disturbance in the germ-cells. But this is 

 very different from the transmission of hardened liver or any 

 other specific modification. Everyone knows that alcoholism of 

 parents does not make for vigorous progeny, but it must be 

 insisted that this does not bear very directly on the technical 

 problem of the transmission of modification. In most cases 

 what is inherited in the alcoholic lineage (rarely a long one) is 

 a constitutional defect, e.g. lack of control. In some cases the 

 parental intemperance affects the germ-cells prejudicially ; though 

 in some animals the results of experiments do not corroborate 

 this. It seems to vary with the organism. Finally, the offspring 

 of an alcoholic mother may be badly handicapped before birth, 

 but this has as little bearing on the transmission of acquired 

 characters as the fact that whisky babies do not thrive. It is 

 not legitimate to re-define "acquired characters" ; the term means 

 modifications of structure acquired in the individual lifetime 

 as the direct result of peculiarities in surroundings, food, and 

 function. 



Professor Weismann laid emphasis on the somewhat subtle 

 idea that the complex germ-plasm, which somehow contains the 

 whole inheritance, might be prompted to vary by fluctuations in 

 the nutritive stream of the body. Just as poisons in the blood 

 may deteriorate the germ-cells in definite ways, so the gentler 

 influence of slight changes in nutrition may induce the germ-cell 

 to internal rearrangements which are by and by expressed as 

 profitable variations. It should not be forgotten that differences 

 in diet determine whether the grub of a bee is to develop into 

 a worker or into a queen. 



It seems fair to say that the problem of the origin of varia- 

 tions is not so dark as it was in Darwin's time. At the same 

 time no one can pretend to understand the emergence of the 

 distinctively new. The germ-cell is a living creature in a single- 

 cell phase of being, and it may be that its variations are the out- 



