1900.] on Facts of Inheritance. 357 



there is not the slightest attempt to discriminate between true 

 reversion (i.e. the re-expression of latent ancestral characters) and 

 the phenomena of arrested development, or of abnormalities which 

 have been induced from without. Often, too, there has been no 

 scruple in naming or inventing the ancestor to whom the reversion is 

 supposed to occur, although evidence of the pedigree is awanting ; 

 and the vicious circle is not unknown of arguing to the supposed 

 ancestor from the supposed reversion, and then justifying the term 

 reversion from its resemblance to the supposed ancestor. Little 

 allowance has been made for coincidence, and the postulate of 

 characters remaining latent for millions of years is made as glibly as 

 if it were just as conceivable as a throw-back to a great-grandfather. 

 I do not see any way out of the theory that characters may lie 

 latent for a generation or for generations, or in other words that 

 certain potentiabilities or initiatives which form part of the heritage 

 may remain unexpressed for lack of the appropriate liberating 

 stimulus, or for other reasons, or may have their normal expression 

 disguised. The drone bee has a mother, the queen, but no father, 

 for the eggs which develop into drones are not fertilised, yet his 

 structure differs from that of the queen in other points besides those 

 immediately related with sex, and he may in his turn be the father 

 of future queens and workers. At the same time it does not follow 

 that the re-appearance of an ancestral character not seen in the 

 parents is necessarily due to the re-assertion of latent elements in 

 the inheritance. It may be a case of ordinary regression ; it may be 

 a case of arrested development ; it may be an extreme variation 

 whose resemblance to an ancestral characteristic is a coincidence ; 

 it may be an individually acquired modification, reproduced apart 

 from inheritance, by a recurrence of suitable external conditions, and 

 so on. In short, what are called reversions are probably in many 

 cases misinterpretations. 



V. Galton's Law. 



The most important general conclusion which has yet been 

 reached in regard to inheritance is formulated in Galton's Law. Mr. 

 Galton was led to it by his studies on the inheritance of human 

 qualities, and more particularly by a series of studies on Basset hounds. 

 It is one of those general conclusions which have been reached 

 statistically, and I must refer for the evidence and also for its 

 strictest formulation to the revised edition of Mr. Pearson's ' Grammar 

 of Science.' 



As we have seen, it is useful to speak of a heritage as dual, half 

 derived from the father and half from the mother. But the heritable 

 material handed on from each parent was also dual, being derived 

 from the grandparents. And so on, backwards. We thus reach the 

 idea that a heritage is not merely dual, but in a deeper sense multiple. 



Though a comparison with the inheritance of property cannot be 



