PLANT HYBRIDIZATION BEFORE MENDEL 135 



The plants differed from one another in height, habit, form of 

 the foliage, coloration of the stems and flowers, degree of fer- 

 tility, size of the fruits and their degree of spinescence. The 

 various vegetative characters are given in a descriptive man- 

 ner and in some detail, but without classification. 



"To sum up," he says, "the forty-five plants of the two lots, consti- 

 tute, so to speak, as many individual varieties as if, the bond which 

 attached them to the specific types being broken, their vegetation had 

 wandered in all directions. This it is that I call 'disordered variation' 

 [variation desordonnee], in opposition to another very different manner 

 of varying of which I shall speak farther on." (p. 157.) 



The idea seems not to have suggested itself to Naudin that 

 there could necessarily be any ascertainable law underlying the 

 confusion which the variations in question represented, or that 

 any quantitative study of the characters of the plants of the 

 second generation was therefore necessary. 



In an article, "Sur les plantes hybrides," published in the 

 Revue Horticole for 1861, Naudin had already arrived from his 

 experiments at certain conclusions regarding the hybrid condi- 

 tion. The hybrid, he says (4b, p. 397), may have characters of 

 two orders : The first, to which in general the most attention is 

 given, is the mixture in diverse proportions of the characters 

 peculiar to each of the parental forms, and which constitutes the 

 hybrid a form intermediate between the two. This mixture of 

 characters may be an equal distribution of the characters of the 

 two parents, but more often it is very unequal, in which case the 

 hybrid more or less sensibly approaches one of the two species. 

 In general, this fusion of characters is seen in all the parts of 

 the hybrid, but there are cases, more rare, as Naudin states : 



". . . where the characters dissociate [se dissocient] to occupy sepa- 

 rately and exclusively certain organs, so that the hybrid appears to be 

 formed of heterogeneous parts, borrowed from the two species, and as 

 it were, soldered to one another." (p. 397.) 



The hybrid orange, in which the fruit is lemon in certain por- 

 tions and orange in others, is cited as "one of the best known 

 examples of this form of disjunctive hybridity." 



Often the two orders of characters exist simultaneously in 

 the same hybrid plant, but is it not rare, says Naudin, for one 

 of them to appear alone. 



"it is a rare case where a hybrid resembles exclusively one of the two 



