Roberts: The Founders of the Art of Breeding 



265 



from the type, but is placed upon the 

 line which leads in the desired direction, 

 and the other is placed in an opposite 

 direction, but departing considerably 

 from the type, we shall not neglect 

 nevertheless to follow this latter, because 

 with it the breaking-up of atavism is 

 more advanced" (p. 31). 



The necessity of fixing upon some 

 single individual plant as the basis of 

 selection is referred to by Verlot in the 

 following terms: "We ought, then, to 

 recognize that it is necessary to take 

 account for the choice of the seed- 

 bearers, not only of the external char- 

 acters but even of the idiosyncrasy of 

 each one of them. Now since this 

 does not manifest itself except by its 

 effects, we shall, if a variation seems to 

 present some difficulties in becoming 

 fixed, have to examine separately the 

 products of each of the seed parents 

 and make our choice bear upon those 

 which present, in the least pronounced 

 degree, atavism, or the tendency to 

 return to the primitive type" (p. 32). 



Verlot's experience with and observa- 

 tions upon hybrid plants, as coming 

 from an experienced horticulturist, are 

 interesting, and, to the practical plant 

 breeder, valuable. Regarding the now 

 well-understood fact of the gradual dis- 

 appearance of the hybrid forms through 

 segregation, he says: "Their fertility is 

 of short duration, through the more or 

 less rapid return of their products to 

 the types which have given them birth" 

 (p. 25). 



Regarding the general aspects of 

 plant hybrids, he adds: "All their 

 characters, of whatever nature they 

 may be, with the exception of a more 

 considerable development of the organs 

 of vegetation, are, in general, inter- 

 mediate between those of the parents, 

 but always limited by them" (p. 25). 

 Regarding the matter of the bounds or 

 limits of the hybrid characters he 

 remarks elsewhere: "Let us call atten- 

 tion to a circumstance always constant 

 in the hybrids, which we have to con- 

 sider, that is, the absence in the products 

 of colors other than those, or a com- 

 bination of those of the parents. We 

 shall insist upon this characteristic, 



because we shall have occasion to^ 

 recur to it; it will serve us to establish 

 the fact that up to now the facts prove 

 that, by hybrid fecundations, one will 

 obtain, in whatever part of the plant 

 they present themselves, the variations 

 of color only, limited to those of the 

 parents" (p. 18). 



Since Verlot's view regarding the 

 nature of a hybrid was the conventional 

 one that it consists of a cross between 

 what are commonly called distinct 

 species, he was led to notice the very 

 common fact of comparative sterility 

 in these cases. Noting the well-known 

 characteristic of augmented vegetative 

 growth in hybrids, he is led to ascribe 

 the seed sterility to the latter, a con- 

 clusion easily if naively arrived at 

 from the well-known inverse relation 

 between undue vegetative luxuriance 

 and seed reproduction. As an instance 

 of intermediacy, Verlot alludes to the 

 matter of height : "In crossing an almost 

 dwarf species with the pollen of a taller 

 species . . the seeds of this cross 



will undubitably produce individuals 

 taller than was their mother" (p. 44). 



Regarding intermediateness in size in 

 flowers, he says: "In crossing a species 

 parviflora by its variety grandiflora we 

 shall be able ... to obtain indi- 

 viduals with flowers larger than those 

 of their mother ... by crossing 

 one is able then to create a race or a 

 variety in which the size of the flowers 

 will be augmented" (p. 47). With 

 regard to the same matter in respect to 

 earliness and lateness, he says: "Sup- 

 posing one crosses a very early plant 

 with its very late variety, or vice versa, 

 one will only be able to obtain varieties 

 intermediate between the parents in 

 earliness or lateness" (p. 50). 



Regarding fragrance he mentions the 

 case of a cross between Rhododendron 

 ciliatum (odorless) and R. Edgeworthii 

 (very fragrant), the hybrid being less 

 intensely fragrant than the pollen 

 parent (p. 31). In the matter of color 

 intermediateness he makes the state- 

 ment: "Once obtained, white coloration 

 is able to serve, either by crossing or 

 by hybridization, in the production of 

 new variations, ordinarily intermediate 



