136 PLANT HYBRIDIZATION BEFORE MENDEL 



parents ; that is to say reproduces identically one of the two specific 

 forms." (p. 397.) 



In the same article Naudin reports upon an experiment in 

 crossing Petunia nyctaginaeflora, with white corolla and yellow- 

 ish pollen, by Petunia violacea, with purple corolla and violet- 

 blue pollen. Naudin says : 



"Our experiments have taught us that the hybrids in the first genera- 

 tion are very uniform in most of the species." (p. 398.) 



Of thirty-six plants derived from the above cross, thirty-five 

 were very much alike, with lilac flowers and bluish pollen. The 

 second generation is recorded in some detail. Ten plants resem- 

 bled P. vwlacea in form and color, so that it was impossible to 

 distinguish them from the type. Nineteen plants had flowers 

 white or very feebly rose-colored, with violet throat and with 

 grey-blue pollen. Sixteen plants had flowers more or less lilac. 

 One only had white flowers. In the third generation 1 16 plants 

 were grown (in 1856), concerning which it is not necessary to go 

 into detail. 



The conclusion which Naudin drew from his Petunia experi- 

 ments, repeated, as he says, several times, was to the effect that 

 at least in the genus in question : 



". . . the hybrids have no constancy, and that one is not able to 

 count upon the sowing of their seeds to reproduce and preserve the 

 varieties which crossing has caused to arise." (p. 398.) 



19. Verio fs Memoir on the Breeding of Plants. 



In 1865, B. Verlot of the Jardin des Plantes at Paris published 

 a brief memoir, which in 1862 had received a prize from the 

 Imperial and Central Horticultural Society, the thesis of which 

 was as follows : 



"To demonstrate the circumstances which determine the production 

 and fixation of varieties in ornamental plants." 



The memoir is of interest as thoroughly and typically em- 

 bodying the general point of view of the day concerning hybrid- 

 ization and the origin of new varieties, while affording at the 

 same time much matter of interest from the standpoint of prac- 

 tical horticulture. 



Verlot presented the view that, while the causes of variation 

 are unknown, they arise under definable circumstances, chief 



