48 PLANT HYBRIDIZATION BEFORE MENDEL 



to speak more properly, to bring these latter themselves into a complete, 

 and, especially from the one side, into masses of unlike size than were 

 demonstrated from the preceding reproduction." (i, p. 43.) 



Kolreuter's "Zweite Fortsetzung" to the 'A'orlauiige Nach- 

 richt," published in Leipzig in 1764, gives an account of 49 ex- 

 periments, of which 29 were distinctly crossing experiments, the 

 remainder being experiments involving the use of the plant's own 

 pollen, simultaneously with that of another species. The species 

 used in the crosses were as follows : 



Species Number of crosses 



Verbascum 4 



Nicotiana 12 



Dianthus 7 



Hibiscus 2 



Datisca 2 



Mirabilis l 



Leucojum l ' 



Of the twelve Nicotiana crosses seven, and of the seven Dian- 

 thus crosses four are compound. 



Of the four Verbascum crosses, each with the same female, but 

 V. ith different male parents, it is reported that all were inter- 

 mediate, neither the one nor the other of the parents having the 

 preponderance. 



Concluding in his own mind that the live tobacco forms rus- 

 tica, inajor, paniculata^ glutinosa^ and perennis, were simply va- 

 rieties of the same species, these, he says : 



"l pollinated the past year (1762) reciprocally together, and obtained 

 through this manifold combination always the most complete capsules," 

 and the plants obtained from these seeds, "held in all parts the mean 

 between their parents, and were just as fruitful as those could ever 

 have been." (p. 118.) 



This fact was evidence to Kolreuter's mind that the five sup- 

 posed "species" were merely varieties of the same natural species. 



Regarding crosses between {Nicotiana glutinosa X ^'- peren- 

 nis) and (Nicotiana glutinosa X ^^- major fl. alb.) Kolreuter 

 found that the plants were identical in type with those of the 

 reciprocal cross. Of the former he says fp. 120) : 



"They did not come into full bloom, but one saw from their whole 

 appearance otherwise that they were as like those of the reciprocal ex- 

 periment, as one egg like another." 



Of the second cross he remarks : 



"So far as its resemblance is concerned, there was not the least differ- 



