PLANT HYBRIDIZATION BEFORE MENDEL 91 



These seeds, however, sown the following year, 



"uniformly afforded plants with colored leaves and stems, and purple 

 flowers ; and these produced gray peas only." {ib., p. 379.) 



In the case of Goss's "Blue Prussian" Pea, Knight continues, 

 the cotyledons being blue in color, and this color being percepti- 

 ble through the semi-transparent seed-coats, caused the latter to 

 appear blue, although they were really white. He concludes : 



"The color of the cotyledons only was, I therefore conceive, changed, 

 whilst the seed-coats retained their primary degree of whiteness." {ib., 

 P- 379.) 



Knight therefore finally holds that the opinions that neither 

 the color of the seed-coats, nor the form, taste, or flavor of 

 fruits, are ever affected by the immediate influence of the pollen 

 of a plant of another variety or species, are well-founded {ib.^ 

 p. 380.) 



Knight thus built up an opinion of a general character regarding 

 the fruits of plants, based upon his experiments involving the seed- 

 coats alone. However insufficient such a conclusion seems at the 

 present time, drawn from such partial premises, it is explainable 

 by the fact that the morphology of seed-development was, at 

 that time, little understood, so that the factors affecting any one 

 part of the fruit, such as the seed-coats, might easily be conceived 

 of as similarly affecting other parts. 



The following examples will serve to illustrate the nature of 

 his results. Of his currant crosses, he says : 



"Five varieties, three red* and two white, out of about two hundred, 

 appeared to me to possess considerably greater merits than either of 

 their parents, and one of the red will, I believe, prove larger than any 

 red currant now in cultivation." 



By crossing the "Noblesse" peach (female) by "Nutmeg" 

 (male), he obtained about twenty seedlings, of which three: 



"Appeared better peaches than I previously possessed." Of one of these 

 he says : "its fruit has attained a more uniform degree of perfection than 

 I have ever witnessed in any other variety. The trees have also been free 

 from every vestige of mildew, in a situation where the disease is very 

 prevalent, and have entirely escaped the attacks of insects." 



In 1809, Knight gave a paper before the Royal Society, en- 

 titled : "On the comparative influence of male and female par- 

 ents on their offspring." (3c.) 



Prompted by the conception of Linnaeus, "that the character 



