6i2 THE WONDER OF LIFE 



dogmatism, between liberal and conservative moods, so 

 the germ- plasm may have what correspond to originative 

 and fixative moods. 



As an instance of the stabihty of the germ-plasm, even 

 when violently treated, we may take Dr. D. D. Whitney's 

 investigation of the eSect of alcohol on generations of 

 Eotifers. He studied four strains of parthenogenetic 

 Rotifers, originally descended from one female, for twenty- 

 eight successive generations. One strain was kept as a 

 control, and the other three strains were kept in a quarter 

 per cent., a half per cent., and one per cent, of alcohol. The 

 rate of reproduction was lessened in the alcohohc strains 

 and the resistance power was lowered. In the eleventh to 

 fifteenth generations of the one per cent, alcohol strain, the 

 individuals showed a decidedly lower resistance power. They 

 exhibited a markedly increased susceptibiUty to copper 

 sulphate which was used as a test of resistance. The result 

 showed, then, the evil effects of alcohol. But whether it 

 showed the hereditary evil effects or not remained to be 

 seen. 



When the alcohol was removed in generations eleven to 

 twenty-two, the rate of reproduction increased noticeably in 

 the very first generation, and in the second equalled that 

 of the control strain. Individuals of the second generation 

 after the alcohol had been removed were no more susceptible 

 to copper sulphate than those which had never been alco- 

 holized. The general conclusion is that the grandchildren 

 possess none of the defects caused by alcohol in the grand- 

 parents. The alcohol, in the small percentages used, 

 affected only the body- tissues of the Rotifers, which is not, 

 of course, to be interpreted as meaning that chronic alcohol- 

 ism in man may not affect the germ-cells. Dr. Whitney 



