PLANT HYBRIDIZATION BEFORE MENDEL 243 



bits are themselves liable to some small change during the process of 

 transmission. Inheritance may therefore be described as largely if not 

 wholly 'particulate,' and as such it will be treated in these pages." (2a, 



P- 7-) 



"We appear, then, to be severally built up out of a host of mmute 



particles, of whose nature we know nothing, any one of which may be 

 derived from any one progenitor, but which are usually transmitted in 

 aggregates, considerable groups being derived from the same progeni- 

 tor. It would seem that while the embryo is developing itself, the par- 

 ticles, more or less qualified for each new post, wait as it were in com- 

 petition to obtain' it. Also that the particle that succeeds must owe its 

 success partly to accident of position and partly to being better qualified 

 than any equally well-placed competitor to gain a lodgment." (2a, p. 9.) 



It is the latter conception that was concretely exemplified in 

 Mendel's principle of dominance, to which it appears that Galton 

 offered no corresponding hypothesis. Galton, however, recog- 

 nized the existence of "heritages that blend," and "heritages that 

 are mutually exclusive." For the former he cites the case of human 

 skin color, referring to crosses between the white and the negro, 

 adding : 



"it need be none the less 'particulate' in its origin, but the result may 

 be regarded as a fine mosaic too minute for its elements to be distin- 

 guished in a general view." (ib., p. 12.) 



It appears that the conception of "particulate inheritance" in- 

 terested Galton, since the quality of his mind was such as to de- 

 mand concrete expressions for the interpretation of inheritance 

 phenomena. The facts indeed increasingly appear to show "that 

 much so-called "blended inheritance" is actually particulate in 

 character. 



As an example of "heritages that come altogether from one 

 progenitor to the exclusion of the rest," he cites eye-color. 



"Eye-colour," he says, "is a fairly good illustration of this, the chil- 

 dren of a light-eyed and of a dark-eyed parent being much more apt to 

 take their eye-colours after the one or the other than to have inter- 

 mediate and blended tints." (ib., p. 12.) 



Galton recognized the existence of "latent" characters. 



"The total heritage of each man must include greater variety of ma- 

 terial than was utilized in forming his personal structure. [2a, p. 18.] 

 The existence in some latent form," he says, "of an unused portion is 

 proved by his power already alluded to, of transmitting ancestral char- 

 acters that he did not personally exhibit. Therefore the organized struc- 

 ture of each individual should be viewed as the fulfillment of only one 

 out of an indefinite number of mutually exclusive possibilities. His 

 structure is the coherent and more or less stable development of what 



