PLANT HYBRIDIZATION BEFORE MENDEL 131 



does not follow therefrom that these intermediate forms are always at 

 an equal distance from those of the two species." (4c, p. 189.) 



He goes on to remark upon the vagueness with which this rela- 

 tive approximation is determined, resting as it does largely upon 

 a basis of opinion. He also calls attention to the fact, that some- 

 times hybrids resemble one of the two parents in certain parts, 

 and the other in other parts. 



Regarding segregation in the second hybrid generation, he 

 says : 



"Very often, to the so perfect uniformity of the first generation, there 

 succeeds an extreme medley of forms, some approaching the specific 

 type of the father, the others that of the mother. . . . (4c, p. 190.) 



"it is, as a matter of fact, in the second generation that this dissolution 

 of the hybrid forms commences in the great majority of cases. . . . (4c, 

 p. 190.) 



"Among several of these hybrids of the second generation, there is 

 a complete return to one or the other of the two parental species, or to 

 both, and diverse degrees of approach to these species." (4c, p. 191.) 



Naudin now comes to what he regards as the philosophical ex- 

 planation of these facts. 



"All these facts are naturally explained by the disjunction of the two 

 specific essences, in the pollen and in the ovules of the hybrid. A hybrid 

 plant is an individual in vjhich are found united two different essences, 

 having their respective modes of development and final direction, which 

 mutually counter one another, and which are incessantly in a struggle 

 to disengage themselves from one another!' (4c, p. 191.) 



The above is Naudin's statement of the "law of disjunction." 

 It is essentially a statement of the principle operating in what is 

 known as Mendel's Law, but must be regarded rather as a philo- 

 sophical inference, or divination of the truth, than as a scientific 

 conclusion derived from the data of specific experiment. 



"The hybrid," says Naudin, "in this hypothesis, would be a living 

 mosaic, in which the eye would not discern the discordant elements as 

 long as they remained intermingled ; but if, in consequence of their 

 affinities, the elements of the same species, mutually approximating one 

 another, agglomerate in rather considerable masses, there may result 

 therefrom parts discernible to the eye, sometimes entire organs, .etc." 

 (4c, p. 192.) 



Naudin concludes that the pollen and the ovules, and the pollen 

 especially, "are the parts of the plant where the specific disjunc- 

 tion takes place with the most energy." f4c, p. 193.) 



He goes on to suppose (and here, perhaps, he comes close to a 

 statement of Mendel's view), viz.: 



