162 ERASMUS DARWIN 



I quote it only because it accords with a bent or 

 tendency of many modern minds that are in revolt 

 against the mechanicians, who will allow no soul to 

 man nor spirit or purpose or ruler or maker to the 

 world. We have seen how this temper is the cause of 

 a perpetual harking back to the things of the past, 

 to the time when man thought as a child, finding 

 or trying to find some comfort in them some 

 justification of their mental attitude. If some of 

 our physicists are coming to think that an 

 electron may be spirit as well as substance, it 

 may be profitable as well as soothing to return to 

 Dr. Henry More. 



Erasmus Darwin was born well in the Age of 

 Reason, when miracles had ceased, and he accord- 

 ingly sought for a natural explanation of this pheno- 

 menon and attributed it to tradition. Now it is true 

 that most of the acts of social and gregarious animals 

 are due to tradition, but unfortunately for this theory 

 we know that very many of the migrants are solitary 

 and that their young travel alone to their destina- 

 tions. Finally this notion throws no light on the origin 

 of the instinct. Nevertheless, it has persisted in a 

 modified form or in various forms, and may be con- 

 sidered the parent of the idea of traditional, racial, 

 and unconscious memory as the cause of migration. 

 Romanes adopted this view, and also stated that 

 migration was founded on a sense of direction. 

 Alfred Russel Wallace also held it, but not satisfied 

 that the explanation was a sufficient one, he gathered 

 up the old simplicities and put them in. He says: 



