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HORTICULTURAL SOCIETY OF NEW YORK. 



sowings, both with the seed of a flesh-colored mother, which showed this 

 division. One of them gave 489 individuals with 83% flesh-colored and 17% 

 white ones. The other consisted of 156 specimens, and of them 80% were 

 flesh-colored and 20% white. 



The most interesting results are evidently to be expected when one of the 

 two pairs of antagonistic characters has become constant while the other has 

 remained hybrid. From the table given above two of these combinations are 

 possible in one case, viz. : 



Constant flesh-colored + Delila X white. 

 Constant Delila -j- Flesh-colored X white. 



It is evident that in both of the combinations the hybrid must show the 

 sum of the constant and the dominant characters, or flesh-colored -f- Delila, 

 which gives the dark-red original type. Such hybrids cannot be distinguished 

 either from those where both pairs are hybrid, nor from those where both the 

 elements have become constant. All of these are dark-red, and it is therefore 

 among the 56.25% dark-red specimens that chance must help us to work out 

 the different types, if it is not possible to -cultivate the progeny of a large 

 enough portion of them to secure the same result directly. 



When fertilizing a hybrid of the type Constant flesh-colored -j- Delila X 

 white all the children will be flesh-colored. As to the other element they will 

 split up into 75% Delila and 25% white. The result will be : 



75% Delila + Flesh-color = Dark-red. 

 25% White -f Flesh-color Flesh-color. 



I counted the progeny of a dark-red hybrid and found among 390 flowering 

 children 74% dark-red and 26% flesh-colored. The mother was therefore a 

 hybrid of the type in question. 



In the same way the Delila component may be constant and the flesh- 

 color hybrid, and the calculation gives : 



75% Delila + Flesh-color = Dark-red. 



25% Delila -j- White = Delila. 



I also observed this case among my sowings, and counted among the 

 children of the dark-red hybrid : 



79% Dark-red. 



21% Delila. 



From these experiments it is clear that the different combinations which 

 may be calculated by Mendel's laws, on the assumption that the color of wild 

 species is composed of two principal elements, viz., flesh-color and Delila, are, 

 in fact, to be met with when the individual hybrids of the second generation 

 are self-fertilized, and the progeny or third generation is cultivated separately 

 for each of them. This method may be called a hybridological analysis. 



Once found, the result may be calculated by the method of hybridological 

 synthesis, and in a more easy and direct way. With this object in view I 

 cultivated in the summer of 1899 three specimens of the flesh-colored variety 

 and fertilized them with the pollen of the Delila type. I cultivated their prog- 

 eny in separate lots, and had 124, 142 and 187 individuals from the three 

 mothers, or 453 in all. But all of them without exception produced red 

 flowers, the same dark- red type as the original form. This was the proof that 

 this original color may be built up from its constituents, and that the varieties 



