598 Principles of Gardening 



property in a much higher degree than the lower ones; this 

 proceeds merely from their greater age, as, when younger, they 

 form buds as easily as the others. The appearance of these 

 buds takes place at the same time as the roots at the base; as 

 long as the leaves are on the plant they only sprout when the 

 atmosphere is very damp and warm, or when, by making in- 

 cisions in the leaf-stalk, the returning sap is interrupted. In 

 Bryophyllum, they are seated like a conical knob in the axils of 

 the notches, and are connected with the bundle of spiral vessels 

 which form the veins of the leaf. 



From this circumstance, the single fruit, or seed-vessel, was 

 said to consist of a fruit-leaf bent over and grown together. In 

 growing together, the pouch was formed which contained the 

 ovula; and this view of the case was applied to all formations 

 of seed, and hypothesis upon hypothesis raised upon it. In the 

 present day this view must be considered erroneous, at least, 

 partly so ; as, among the vast number of plants, there are hitherto 

 but few examples known where buds grow on the edges of the 

 leaves. It may also be remarked, that the ovula never pro- 

 ceed from the edges themselves, but from the bundle of vessels 

 lying on them ; and we have no right to suppose that these 

 vessels are formed by the growing together of the edges of the 

 leaves, when we see in all other cases in nature that the ribs 

 and veins of the leaf give the direction to its form, but usually 

 end before coming to the edge. Propagating plants by leaves, 

 which was adduced as a strong proof of the validity of this 

 opinion, by no means justifies it; for, when roots and buds are 

 formed (though for the most part they only make roots, and 

 many leaves remain for years together, fill the whole pot with 

 roots, and form no buds ; so that, to make sure of succeeding, 

 the axillary bud ought to be removed with the leaf), the latter 

 proceed from immediately above the cut, out of the leaf-stalk, 

 and, except in the above-mentioned cases, never out of the 

 edo-es of the leaf. I do not, however, assert from this, that 

 fruit cannot be formed without an axis; for Nature does not 

 suffer herself to be trammeled with systems. Should there, 

 however, be such a formation of fruit, which, nevertheless has not 

 as yet come under my knowledge, it must take place apparently, 

 as M. Meyen very justly remarks, from the passing over of the 

 axis into the fruit-leaf; and the ovula would be much more 

 likely to spring from the axils of the veins, than from the edges 

 of the leaves. 



That such a form of fructification is possible, but by no means 

 normal, is proved by the circumstance that on many leaves, in 

 favourable situations, buds exactly like those developed from 

 the rudiments of buds have been observed. They were first re- 

 marked by Poiteau on the whole surface of the leaf, springing 



