±28 ON THE DIEECT ACTION OF THE Chap. XI. 



action of the male element, not in the ordinary way on the 

 ovules, but on certain parts of the female plant, or in case of 

 animals on the subsequent progeny of the female by a second 

 male. I may premise that with plants the ovarium and the 

 coats of the ovules are obviously parts of the female, and it 

 could not have been anticipated that they would have been 

 affected by the pollen of a foreign variety or species, although 

 the development of the embryo, inside the embryonic sack, 

 inside the ovule and ovarium, of course, depends on the male 

 element. 



Even as long ago as 1729 it was observed m that white and blue 

 varieties of the Pea, when planted near each other, mutually crossed, 

 no doubt through the agency of bees, and in the autumn blue and 

 white peas were found within the same pods. Wiegmann made an 

 exactly similar observation in the present century. The same 

 result has followed several times when a variety with peas of one 

 colour has been artificially crossed by a differently-coloured variety. 128 

 These statements led Gartner, who was highly sceptical on the 

 subject, carefully to try a long series of experiments : he selected the 

 most constant varieties, and the result conclusively showed that the 

 colour of the skin of the pea is modified when pollen of a differently 

 coloured variety is used. This conclusion has since been confirmed 

 by experiments made by the Eev. J. M. Berkeley. 129 



Mr. Laxton of Stamford, whilst making experiments on peas for the 

 express purpose of ascertaining the influence of foreign pollen on 

 the mother-plant, has recently 13 ° observed an important additional 

 fact. He fertilised the Tall Sugar-pea, which bears very thin green 

 pods, becoming brownish-white when dry, with pollen of the 

 Purple-podded pea, which, as its name expresses, has dark- purple 

 pods with very thick skin, becoming pale reddish purple when dry. 

 Mr. Laxton has cultivated the tall sugar-pea during twenty years, 

 and has never seen or heard of it producing a purple pod : neverthe- 

 less, a flower fertilised by pollen from the purple-pod yielded a pod 

 clouded with purplish-red which Mr. Laxton kindly gave to me. 

 A space of about two inches in length towards the extremity of the 

 pod, and a smaller space near the stalk, were thus coloured. On 

 comparing the colour with that of the purple pod, both pods having 

 been first dried and then soaked in water, it was found to be identi- 

 cally the same ; and in both the colour was confined to the cells lying 

 immediately beneath the outer skin of the pod. The valves of the 



127 ' Philosophical Transact./ vol. ' Bastarderzeugung,' 1849, ss. 81 and 

 xliii., 1744-45, p. 525. 499. 



128 Mr. Goss, in 'Transact. Hort. 129 'Gari. Chron.,' 1854, p. 404. 

 Sot.,' vol. v. p. 234 : and Gartner, 13 ° Ibid., 1866, p. 900. 



