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JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



But little, if anything, is known as to the immediate causes of many 

 instances of sporting. Varying degrees of nutrition seem to govern them 

 to some extent ; thus a branch of a beech or other tree may suddenly bear 

 deeply dissected leaves. Such have given rise to " cut-leaved " varieties. 

 Now, as there is obviously less material in a slashed leaf than in an entire 

 one of the same area included within the same general outline, it is not 

 unreasonable to assume that from some cause or other the bough had less 

 nourishment at its disposal wherewith to make its leaves perfect. But a 

 peculiarity is that, once formed, the "habit" of making them may 

 become perpetuated ; for, as said, if such a bough be propagated a cut- 

 leaved tree will result. Conversely, a single bough of such a tree may 

 suddenly " revert " to the normal character, and produce leaves like the 

 original and ordinary beech- tree. Nutrition, too, is the chief cause of the 

 production of garden varieties of vegetables. 



It is also to some extent " infectious," so to say ; for M. Carriere, in 

 a work entitled Production et fixation des Varietes dans les Vegetaux, 

 states that a cut-leaved branch of a beech having been grafted upon a 

 common beech, subsequently all the branches above and on the same side 

 as the graft bore divided leaves, while all on the other side of the tree bore 

 ordinary leaves. 



There is a difficulty in drawing any sharp line of difference between 

 sports, monstrosities, and varieties, especially under cultivation ; and the 

 degree of difference is a' very arbitrary matter with many cultivators, who 

 issue new "varieties." For example, the old form of tomato with a 

 ribbed surface "was the result of a monstrous (multifold) flower, like the 

 many-petalled 'Victoria ' Forget-me-not ; but compared with the globular 

 fruit from a normal flower, the former would be called "variety," if not a 

 " monstrosity." 



Moreover, many a so-called sport on one plant, which never previously 

 was known to bear it, may be of normal and regular occurrence on 

 another plant, when it would not be so regarded at all. 



Stems, fastigiate Sports. — The direction of the boughs may suddenly 

 vary. Thus the ordinary yew has horizontal boughs, the short stalks 

 of the leaves twisting so as to bring them into one plane at right 

 angles to incident light. In the "fastigiate" variety, or the Irish 

 yew, the boughs are erect, and the leaves spread out all round the 

 branches. The cypress and the tall Lombardy poplar are similar 

 varieties of trees originating from others, which have a spreading habit. 



Dr. Falconer says the English Ribston-pippin apples, a Himalayan 

 oak, Prunus and Pyrus, assume in the hotter parts of India a fastigiate 

 or pyramidal habit. A Chinese tropical species of Pyrus naturally 

 has this habit of growth (Darwin, "An. and PI. under Dom." ii., p. 277). 

 It is not usually hereditary, but Darwin mentions cases (op. cit. i. 361). 

 All Lombardy poplars were derived from the East, so that temperature 

 appears to be the cause. 



A similar sport to that of the yew occurred in another member of the 

 same family, viz. Cephalotaxus pedunculata, var. fastigiata. Plants 

 having been raised by cuttings of what was known as Podocarpus 

 koriana (with scattered leaves), one of these produced whorled branches, 

 the leaves on which were horizontal as in an ordinary yew. The inter- 



