PLANT HYBRIDIZATION BEFORE MENDEL 139 



tion is so thoroughly typical of the thought of his time, viz., that 

 variation is in consequence of the "breaking up" of the "type," 

 and that selection ipso facto, intensifies the variation in the 

 direction selected for, that it is a matter of interest to present 

 here the view expressed. 



"if a variation is produced in a direction other than that toward 

 which one tends, it ought not to be abandoned for that; one will have 

 more chance to obtain new variations in sowing a deviation from the 

 type, even in a diametrically opposite direction, than in sowing anew 

 the type itself. In the deviation there is already a tendency toward 

 perturbation, and toward the beginning of the destruction of atavism." 

 (6, p. 31-) 



Another interesting example of the older point of view regard- 

 ing plant improvement is Vilmorin's opinion, quoted by Verlot, 

 which is here reproduced to show how thoroughly the primary 

 idea concerning the "breaking up of the type" in order to bring 

 about "variation" entered into the thought and operations of 

 pre-Mendelian breeders. 



"To obtain from a plant not yet modified varieties of a kind deter- 

 mined in advance, I will first set myself to making it vary in some 

 direction or other, choosing for the reproducing factor, not that one of 

 the accidental varieties which would most nearly approach the form 

 which I have proposed to myself to obtain, but simply that which 

 would most differ from the type. In the second generation, the same 

 care would make me choose a deviation, the greatest possible at first, 

 the one most different, in a word, from that which I would have chosen 

 in the first place. Following this direction for several generations, there 

 necessarily ought to result, in the products obtained, an extreme ten- 

 dency to vary; there then results again, and that is the principal point 

 according to me, that the force of atavism, asserting itself counter to 

 very divergent influences, will have lost a great part of its power, or, 

 if one ventures to make use of this comparison, it will exert it always 

 in a broken line." (6, p. 28.) 



Man's relation to the fixation of characters in new races of 

 plants is stated by Verlot in the usual manner prevalent in the 

 days before Mendelian analysis : 



"In brief, gardeners have remarked, ^with reason, that a plant newly 

 introduced is very susceptible to vary. This fact, it is conceived, has 

 nothing surprising about it. It confirms that which we have previously 

 said, that a variety, whatever it might be, had need, in order to become 

 fixed, of being cultivated for a greater or less length of time, until one 

 had finally come to maintain with it the tendency not to depart from 

 being that which he had made it." (6, p. 70.) 



In other words, the idea then prevalent and more or less im- 

 perfectly expressed was that, in some unknown manner, man, by 



