602 APPENDIX. 



shield bud of C. purpureus beneath the bark of C. laburnum, and we 

 have many records of Pears being altered in size, colour, flavour, and 

 time of ripening, owing to their having been grafted on the Quince stock. 

 Hence it will be seen that grafting is not to be relied on as a certain 

 means of reproducing either varieties or species in a pure state, but, on 

 the contrary, may in some cases be employed to change the colour or 

 other attributes of a species or variety in a manner closely analogous to, 

 if not identical with, hybridism and cross-fertilisation. 



Mr Maule has succeeded in grafting pieces of a Potato on the common 

 Bitter-sweet (Solanum Dulcamara) as a stock, and was surprised to find 

 that the roots of the stock developed little tubers ; and a similar result is 

 said to have since been obtained by grafting the Jerusalem Artichoke 

 (Helianthus tuberosus] on the common Sunflower (H. annuus] as a 

 stock, tubers having been developed on the roots of the Sunflower. 

 Further and carefully - conducted proof experiments in these particular 

 instances are desirable ; nevertheless, the coincidence of those two cases 

 of tuber-development, induced by grafting tuberous species on non- 

 tuberous rooted ones as stocks, is a strikingly suggestive one to gardener 

 and botanist alike, especially when viewed in the light which is now 

 being diffused by the seemingly spontaneous variations of grafted and bud- 

 ded Roses, Laburnums, Pears, Apples, Plums, and Grape-Vines. 



We have so many curious hybrids and variations produced by grafting 

 and by budding, that what is now especially desirable is a series of proof 

 experiments with the parents of these well-known hybrids, reputed graft 

 variations, &c., so as to verify the voluminous observations of cultivators 

 and others, bring out facts, and thus obtain reliable data, or light, by 

 which we may peer still further into the hazy atmosphere of vegetable 

 physiology. The field for carefully-organised experiments of the kind 

 here indicated is too wide for any single-handed investigator ; indeed it 

 is work which rightly belongs to a botanical garden. 



There is one point to which I particularly wish to allude in reference to 

 graft-hybridity namely, the possibility of inducing variegation by mere 

 sap-inoculation, or transfusion of coloured cellular tissue from a variegated 

 plant to a green-leaved one. Blair and Fairchild speak of this ; indeed 

 the fact was observed in a Holly by the first-named author a century and 

 a half ago (see p. 62), and often since, especially in the case of green- 

 leaved Abutilons and Jasmines, which have been budded and which have 

 at once assumed variegated foliage, although the variegated bud inserted 

 died away gradually, that is, refused to "take" or unite with the stock. 

 In the case of variegated Pelargoniums, engrafting a very little cellular 

 tissue from a coloured part of the stem or leaf is amply sufficient to induce 

 variegation in a green-leaved plant : and this subject deserves the attention 

 of cultivators and hybridisers ; since now we can readily induce leaf and 

 stem variegation, it is not only possible, but highly probable, that variega- 

 tion or variation of colour in the flowers, fruits, and resulting seedlings will 

 follow. Another point of great importance to hybridisers and propagators 

 is a knowledge of the extremely variable characteristics possessed by 

 different individuals, not only of the same species, but even of the same 

 variety. This strong individuality of plants has been pointed out by 

 Darwin in the case of Pelargoniums, by Meehan in certain Lilies, by the 

 late Mr Pearson in certain forms of the Moor Park Apricot ; and it is an 

 everyday observation made by all intelligent Orchid-growers and general 

 plants-men. 



In the case of the Wellingtonia, for example, Messrs C. Lee & Son find 

 that the branches of some individual trees root freely as cuttings, while 

 those taken from other individuals, growing apparently under precisely 



