330 THE PRESENT EVOLUTION OF MAN — MENTAL 



Were that so a race that was introduced to alcohol 

 would become, other things equal, increasingly drunken 

 in successive generations, exactly as if by the transmis- 

 sion of acquired traits, for in such a case the son would 

 inherit the father's craving plus an increment to it, 

 caused by the presence of alcohol in the fluids that 

 bathed the father's germs, and would therefore drink 

 more; the grandson would inherit the son's increased 

 craving, plus a further increment caused by the more 

 drunken habits of the latter, and would in consequence 

 drink still more ; so also as regards the great-grandson 

 and subsequent descendants, till, in the presence of 

 alcohol, the race would become more and more unfit, 

 and would ultimately suffer extinction. But, as we 

 have seen, races longest familiar with alcohol manifest 

 the least craving for it, and therefore, d posteriori, we 

 have every reason for believing that alcohol does not so 

 affect the germs as to cause, in the individuals which 

 spring from them, a craving for alcohol greater than 

 would otherwise arise. When, therefore, a drunken 

 son succeeds a drunken father, we must conclude that 

 his tendency to excess is due solely to the inheritance 

 of an inborn trait, and not to the inheritance of an 

 acquired variation, nor yet to any effect produced by 

 the poison on the germ whence he sprang. But since 

 a foetus has nervous structures, drunken habits in a 

 pregnant woman may affect her unborn child, in such a 

 manner as to render the individual into which it 

 subsequently grows more drunken than he would other- 

 wise be. But even in such a case, it is probable that 

 the resulting variation is not of such importance as is 

 commonly supposed ; since between the birth of the 

 affected individual and his anival at an age when, 

 under the ordinary conditions of society, indulgence is 

 possible, so long an interval occurs that the variation 

 is probably entirely lapsed. 



