244 PLANT HYBRIDIZATION BEFORE MENDEL 



is no more than an imperfect sample of a large variety of elements." 

 {ib., p. 18.) 



Galton, in the absence of the chromosome theory of the inheri- 

 tance of what he calls the "elements" or "particles" of the poten- 

 tial heritage, undertakes to classify the "imperfect sample of a 

 large variety of elements," under three possible categories : first, 

 the conception embodied in Darwin's theory of pangenesis ; sec- 

 ondly, "that of a more or less general co-ordination of the influ- 

 ences exerted on each element, not only by its immediate neigh- 

 bours, but by many or most of the others as well," and finally, 

 that of "accident or chance, under which name a group of agencies 

 are to be comprehended, diverse in character and alike only in 

 the fact that their influence on the settlement of each particle 

 was not immediately directed towards that end." {ib.^ p. 19.) 



Galton proposes the idea that the particulate nature of inheri- 

 tance makes it appear that there is really 



". . . no direct hereditary relation between the personal parents and 

 the personal child," but "that the main line of hereditary connection 

 unites the sets of elements out of which the personal parents had been 

 evolved with the set out of which the personal child was evolved. The 

 main line may be rudely likened to the chain of a necklace, and the per- 

 sonalities to pendants attached to its links. We are unable to see the 

 particles and watch their grouping, and we know nothing directly about 

 them, but we may gain some idea of the various possible results by not- 

 ing the differences between the brothers in any large fraternity . . . 

 whose total heritages must have been much alike, but whose personal 

 structures are often very dissimilar." {ib., pp. 19-20.) 



In a discussion which follows as to the nature of stability in 

 the inheritance of the organism, Galton makes a hypothetical sug- 

 gestion as to the behavior in inheritance, or the nature of the 

 hereditary factors concerned. 



"The changes," he says, "in the substance of the newly fertilized ova 

 of all animals . . . indicate segregations as well as aggregations, and 

 it is reasonable to suppose that repulsions concur with affinities in pro- 

 ducing them. We know nothing as yet of the nature of these affinities 

 and repulsions, but we may expect them to act in great numbers and on 

 all sides in a space of three dimensions. . . . Every particle must have 

 many immediate neighbours. . . . We may therefore feel assured that 

 the particles which are still unfixed must be affected by very numerous 

 influences acting from all sides and varying with slight changes of place, 

 and that they must occupy many positions of temporary and unsteady 

 equilibrium, and be subject to repeated unsettlement, before they finally 

 assume the positions in which they severally remain at rest." {ib., 

 pp. 20-1.) 



