100 HYBRIDISING AND CROSS-BREEDING. 



LH&cious and Monoecious Plants. Wichura observes and, as 

 I think, very rightly that dioecious plants which are subjected 

 to fertilisation by insects must necessarily produce hybrids, and 

 especially so if they comprise a great number of species nearly 

 related, growing in close company, and all flowering at the same 

 time. In cultivation, however, all dioecious plants do not 

 flower synchronously, and this is .especially the case with the 

 male and female Aucuba, and with the monoecious Nepenthes 

 and Crotons. M. Carriere, in relating his experience with 

 seedling male and female Aucubas in the ' Revue Horticole,' 

 says that out of several thousand seedlings which he has raised, 

 those which have flowered are, with few exceptions, male 

 plants, and that the few female plants which did appear have 

 flowered much later than the male seedlings that is, several 

 weeks, and sometimes even two or three months. Ccelebogyne 

 ilicifolia, a plant long thought to develop female organs only, 

 has at length been found to produce male organs simulta- 

 neously with the female ones. Dioecious grasses, Palms, and 

 other plants rarely produce fertile seeds in cultivation, owing 

 to the male plant being absent, or on account of their not 

 being in bloom at the same time. Where the male plant 

 blooms earliest, pollen may in most cases be preserved by 

 wrapping it in dry tinfoil or silk -paper; and all hybridisers 

 would add greatly to our knowledge by recording the length of 

 time they have kept pollen in its potent state. In case a 

 female plant blooms, and it is of importance that its flowers 

 should be fertilised, fresh pollen may in many cases be pro- 

 cured by advertisement, or from correspondents abroad or 

 plant-loving friends at home. 



Many hermaphrodite plants are for all practical purposes 

 monoecious that is, contrivances have become developed to 

 prevent self - fertilisation, or their male and female organs 



cence Cytisus Adami"), and Duchartre, " Note sur le Chasselas Panache," 

 in the 'Journal de la Societie Imperiale et Centrale d' Horticulture,' 1865, 

 should also be consulted in connection with Dr Masters's paper. Dr 

 Masters contributes a valuable and. interesting paper "On a Pink Sport 

 from Gloire de Dijon Rose" to the 'Journal of the Royal Horticultural 

 Society,' vol. iv. p. 153, which should be read by all interested in this 

 subject. See also Carriere, ' Production et Fixation des Varieties dans les 

 Vegetaux, ' p. 35; Darwin, 'Variation of Animals and Plants,' 1868, 

 P- 379 j article on "Bud Variation," 'Popular Science Review,' 1872; 

 and "Graft Hybridisation," 'Popular Science Review,' 1871, p. 141. 

 Carriere gives a list of Roses which have originated from sports, and Dar- 

 win gives copious references to the literature on variability among plants. 

 See also 'Gardeners' Chronicle,' 1871, p. 74, and Herbert's ' Amarylli- 

 daceoe,' p. 377. 



