98 PLANT HYBRIDIZATION BEFORE MENDEL 



have usually more white in their flowers when they flower early 

 in the spring, and that the earliest ripening seed of the year is 

 most apt to yield white or particolored seedlings. 



Herbert carried on some experiments with double flowers and, 

 in 1834, undertook an experiment in the improvement of agricul- 

 tural plants, pollinating the Swedish turnip (rutabaga) with 

 pollen of the white, and flowers on another branch of the same 

 plant with pollen of the red-rooted turnip, which he speaks of as 

 producing 



". . . perhaps a greater tonnage than the white, bearing both frosts 

 and unfavorable summers better, and thriving in soils where the white 

 does not succeed." (2c, p. 370.) 



The seeds sown, produced good roots the same season : 



"The leaves differed in appearance from those of the Swedes, and did 

 not, like them, retain the rain-water on their surface." (2c, p. 370.) 



In the following spring, the hybrids came into flower, the flow- 

 ers of the hybrids being, for the most part, bright yellow like 

 those of the male, a smaller number bearing straw-colored flow- 

 ers like the Swedish turnip, but there were no intermediates. 



In a paper entitled "On hybridization amongst vegetables," 

 Jour. Hort. Soc. of London, 2:1-28; 81-107 (1847), Herbert dis- 

 cusses quite at length the species question, and shows how firm 

 the allegiance still remained to the conception that fertile off- 

 spring produced from a cross, constituted prima facie evidence 

 that the parents were within the same species. He says : 



"And that is the use of hybridizing experiments, which I have in- 

 variably suggested ; for, if I can produce a fertile offspring between two 

 plants that botanists have reckoned fundamentally distinct, I consider 

 that I have shown them to be one kind ; and indeed I am inclined to 

 think that, if a well-formed and healthy offspring proceeds at all from 

 their union, it would be rash to hold them of distinct origin." (2d, p. 7.) 



Herbert states {ib., p. 8), that he had had : 



". . . no opportunities, by the help of a powerful microscope, of pur- 

 suing any investigation into the process by which the pollen fertilizes 

 the ovules," 



and goes on to say that, although he could not therefore under- 

 take to contradict those who asserted that the pollen grains, 



"from their own bulk, emitted tubes which reached from the surface of 

 the stigma to ovules in the germen" — a distance, as in certain species of 

 Hymenocallis, amounting to sometimes 12-13 inches — it did not appear 



