PLANT HYBRIDIZATION BEFORE MENDEL 



The important statement then follows : 



325 



"For monohybrids, one has then the proposition that their pollen and 

 their ovules are no longer hybrids, that they have the character pure of 

 one of the parents, and the same proposition may be sustained for the 

 others (di- and polyhybrids), when one considers each time but a single 

 simple character." {ib., p. 846.) 



"From this principle one is able to deduce nearly all the laws which 

 govern the distribution of characters of hybrids." {ib., p. 846.) 



De Vries then gives a table of eleven species, from which, when 



cross-fertilized, he found : • 



". . . for the products, the following proportion of individuals presenting 

 the recessive characters." {ib., p. 846.) 



From these results he deduced the conclusion: 



"We see the recessive character is always near 25 per 100." {ib., p. 846.) 



The author then goes on to state that : 



"The cultivation of a further generation permits making a distinction 

 among the 75 per 100 individuals presenting the dominant character." 



He then cites the results with a poppy having a black basal 

 spot upon the petals, with one having a white spot. Calling the 

 former N, and the latter B, he obtained, as for the preceding, 

 75 per cent N and 25 per cent B, in" the hybrids of the first gen- 

 eration. From the seeds of these hybrid plants, self-fertilized and 

 sowing the seeds from each plant in a separate plot, he obtained 

 for 25 out of the 75 plants bearing N, a pure progeny with black 

 petals, and for the 50 others, a mixture of plants with black 

 petals, and of plants with white petals, In the proportion of 37.5 N 

 to 12.5 B. He concludes: 



