^HaP. XL MALE ELEMENT ON THE MOTHER-FCKM. 429 



crossed pod were also decidedly thicker and stronger than those of 

 the pods of the mother-plant, but this may possibly have been an 

 accidental circumstance, for I know not how far their thickness is a 

 variable character in the Tall Sugar-pea. 



The peas of the Tall Sugar-pea, when dry, are pale greenish- 

 brown, thickly covered with dots of dark purple so minute as to be 

 visible only through a lens, and Mr. Lax ton has never seen or heard 

 of this variety producing a purple pea ; but in the crossed pod one of 

 the peas was of a uniform beautiful violet-purple tint, and a second 

 was irregularly clouded with pale purple. The colour lies in the 

 outer of the two coats which surround the pea. As the peas of the 

 purple-podded variety when dry are of a pale greenish-buff, it would 

 at first appeal that this remarkable change of colour in the peas in 

 the crossed pod could not have been caused by the direct action of 

 the pollen of the purple-pod : but when we bear in mind that this 

 latter variety has purple flowers, purple marks on its stipules, and 

 purple pods; and that the Tall Sugar-pea likewise has jrarple flowers 

 and stipules, and microscopically minute purple dots on the peas, 

 we can hardly doubt that the tendency to the production of purple 

 in both parents has in combination modified the colour of the peas 

 in the crossed pod. After having examined these specimens, I 

 crossed the same two varieties, and the peas in one pod but not the 

 pods themselves, were clouded and tinted with purjuish- red in a 

 much more conspicuous manner than the peas in the uncrossed 

 pods produced at the same time by the same plants. I may notice 

 as a caution that Mr. Laxton sent me various other crossed peas 

 slightly, or even greatly, modified in colour; but the change in 

 these cases was due, as had been suspected by Mr. Laxton, to the 

 altered colour of the cotyledons, seen through the transparent coats 

 of the peas ; and as the cotyledons are parts of the embryo, these 

 cases are not in any way remarkable. 



Turning now to the genus Matthiola. The pollen of one kind of 

 stock sometimes affects the colour of the seeds of another kind, used 

 as the mother-plant. I give the following case, the more readily, 

 as Gartner doubted similar statements previously made with respect 

 to the stock by other observers. A well-known horticulturist, 

 Major Trevor Clarke, informs me 131 that the seeds of the large red- 

 flowered biennial stock, Matthiola annua (JJocardeau of the French), 

 are light brown, and those of the purple branching Queen stock 

 (M. incana) are violet-black; and he found that, when flowers of 

 the red stock were fertilised by pollen from the purple stock, they 

 yielded about fifty per cent, of black seeds. He sent me four pods 

 from a red flowered plant, two of which had been fertilised by their 

 own pollen, and they included pale brown seed; and two "which 

 had been crossed by pollen from the purple kind, and they included 

 all deeply tinged with black. These latter seeds yielded 



131 See also a paper by this ob- Hort. and Bot. Congress of London, 

 server, read before the International 1866. 



