Cross Breeding. By Thomas Andrew Knight, Esq, 379 



the cause of a coloured variety of the Pea having been appa- 

 rently changed into a white variety, by the immediate in- 

 fluence of the pollen in the experiment of Mr. Goss. 



When, in my experiments, the pollen of a gray Pea was in- 

 troduced into the prepared blossoms of a white variety, no 

 change whatever took place in the form, or colour, or size, of 

 the seeds ; all were white, and externally quite similar to 

 others which had been produced by the unmutilated blossoms 

 of the same plant. But these when sown in the following 

 year, uniformly afforded plants with coloured leaves and 

 stems, and purple flowers ; and these produced gray Peas 

 only. When the stamens of the plants which sprang from 

 such gray Peas were extracted, and the pollen of a white 

 variety, of permanent habits, was introduced, the seeds pro- 

 duced were uniformly gray ; but many of these afforded plants 

 w ith perfectly green leaves and stems, and with white flowers, 

 succeeded, of course, by white seed. In these experiments the 

 cotyledons of all the varieties of Peas employed or produced 

 were yellow ; and, consequently, the Peas with white seed- 

 coats retained their ordinary colour, though they contained 

 the plumules and cotyledons of coloured Pea plants. The 

 cotyledons of the Blue Prussian Pea, which was the subject 

 of Mr. Goss's experiments, are, on the contrary, blue; and 

 the colour of these being perceptible through the semi-trans- 

 parent seed-coats, occasioned those to appear blue, though 

 they are really white ; the whole habits of that plant are 

 those of a white Pea. The colour of the cotyledons only were, 

 I therefore conceive, changed ; whilst the seed-coatsretained 

 their primary degree of whiteness. I must consequently 



