Chap. XL 



BY SUCKERS, TUBERS, AND BULBS. 



387 



fruit-trees undergo from being grafted and regrafted on various stocks/ 4 

 were considered by Andrew Knight 85 as closely allied to "sporting 

 branches," or bud-variations. Again, we have the case of young fruit-trees 

 changing their character as they grow old ; seedling pears, for instance, 

 lose with age their spines and improve in the flavour of their fruit. Weeping 

 birch-trees, when grafted on the common variety, do not acquire a perfect 

 pendulous habit until they grow old : on the other hand, I shall hereafter 

 give the case pf some weeping ashes which slowly and gradually assumed 

 an upright habit of growth. All such changes, dependent on age, may be 

 compared with the changes, alluded to in the last chapter, which many 

 trees naturally undergo ; as in the case of the Deodar and Cedar of 

 Lebanon, which are unlike in youth and closely resemble each other in 

 old age ; and as with certain oaks, and with some varieties of the lime and 

 hawthorn. 86 



Before giving a summary on Bud-variation I will discuss some 

 singular and anomalous cases, which are more or less closely 

 related to this same subject. I will begin with the famous case 

 of Adam's laburnum or Gytisus Adami, a form or hybrid inter- 

 mediate between two very distinct species, namely, C. laburnum 

 and purjpureus, the common and purple laburnum ; but as this 

 tree has often been described, I will be as brief as I can. 



Throughout Europe, in different soils and under different climates, 

 branches on this tree have repeatedly and suddenly reverted to both 

 parent-species in their flowers and leaves. To behold mingled on the same 

 tree tufts of dingy-red, bright yellow, and purple flowers, borne on branches 

 having widely different leaves and manner of growth, is a surprising sight. 

 The same raceme sometimes bears two kinds of flowers ; and I have seen a 

 single flower exactly divided into halves, one side being bright yellow and 

 the other purple ; so that one half of the standard-petal was yellow and 

 of larger size, and the other half purple and smaller. In another flower 

 the whole corolla was bright yellow, but exactly half the calyx was purple. 

 In another, one of the dingy-red wing-petals had a bright yellow narrow 

 stripe on it ; and lastly, in another flower, one of the stamens, which had 

 become slightly foliaceous, was half yellow and half purple ; so that the 

 tendency to segregation of character or reversion affects even single parts 



84 M. Carriere has lately described, 

 in the « Revue Horticole,' (Dec. 1, 1866, 

 p. 457), an extraordinary case. He twice 

 inserted grafts of the Aria vestita on 

 thorn-trees (epines) growing in pots; 

 and the grafts, as they grew, produced 

 shoots with bark, buds, leaves, petioles, 

 petals, and flower-stalks, all widely dif- 

 ferent from those of the Aria. The 



grafted shoots were also much hardier, 

 and flowered earlier, than those on the 

 ungrafted Aria. 



85 'Transact. Hort. Soc.,' vol. ii. p. 

 160. 



86 For the cases of oaks see Alph. De 

 Candolle in 'Bibl. Univers.,' Geneva, 

 Nov. 1862 ; for limes, &c, Loudon's 

 ' Gard. Mag.,' vol. xi. 1835, p. 503. 



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