GERMINAL SELECTION 467 



minants. Those that are weaker will tend to become weaker 

 still, those that are stronger will tend to become stronger still, 

 and thus germinal selection fosters and strengthens personal 

 selection. In other words, there is an internal reason for pro- 

 gressive variation (either plus or minus) in the direction of 

 utility. 



A Suggestion. If we admit the concept of representative 

 particles in the germ-plasm, which it seems to us is almost 

 demanded by the facts of particulate inheritance, by the inde- 

 pendent variability and heritability of often trivial peculiarities ; 

 and if we admit the probability of some sort of germinal struggle 

 among these living units, which seems to us warranted by what 

 we know of the behaviour of visible living units and by general 

 biological considerations then it seems at least interesting to 

 ask whether we need limit the conception of germinal struggle 

 to a competition between homologous determinants, as Weismann 

 always does. 



In personal selection, as we have seen, there are three distinct 

 types of struggle classified according to the parties involved 



(a) between kindred or homologous organisms, (b) between 

 organisms which are not akin, and (c) between organisms and 

 the inanimate environment. Logically, we may look for the 

 same three modes of struggle in the course of germinal selection. 

 They might be illustrated (a) by struggle between, say, the 

 maternal and the paternal, or the parental and the grand- 

 parental, homologous determinants of a single determinate ; 



(b) by struggle between determinants of quite different kinds 

 e.g. between determinants of the notochord and the deter- 

 minants of its more effective substitute, the backbone ; and 



(c) by struggle between all or any of the determinants and a 

 disturbing external influence, such as some toxin in the parent's 

 blood or lymph, or some change in the osmotic conditions of 

 the sea-water. Is there any theoretical reason why we should 

 restrict the concept of germinal struggle, as Weismann does, 



