PROPAQA TION BY LEA VES. 



229 



He wished to ascertain if they would produce buds as in other cases, 

 lor he was in hopes they would, as he remarked that the roots in- 

 creased in the pot. At last in the seventh month, for the first time, 

 he saw at the extremity of his two half leaves, buds appearing, as well 

 formed as those proceeding from the base of the petiole of an entire 

 leaf. In June, 1840, these two cuttings had become beautiful and 

 healthy plants, which it was impossible to distinguish from others pro- 

 duced from entire leaves, 



We see from this experiment that it requires double the time to 

 produce a bud from the upper part of some leaves, that it requires for 

 the lower half to produce one ; and that, in propagations by leaves, it 



Fig. 177. 



is not always necessary to take the heel or lower 



Fig. 178. 



end of the petiole with the leaf, 

 which sometimes injures and 

 deforms the shoots. M. Neu- 

 man's experiment proves fur- 

 ther, that wherever cambium 

 can be formed, there are at the 

 same time a number of utricules 

 or germs of buds formed, from 

 which a new plant will be de- 

 veloped when the parent is 

 placed in favourable circum- 

 stances. From this circum- 

 stance, in short, we may con- 

 elude that all the veins may 

 serve for the reproduction of The upper half of 

 The lower half of ike leaf plants. The dots in fig. 178 theophrasta rooted 

 of theophrasta rooted ghow the ^ of the and sending up a 



and sending up a shoot. , ,,. , ,. f . , E. r . shoot. 



half-leaf which were cut off to 



allow of its being put into a small pot ; and this proves that it is only 

 the middle rib (or prolongation of the petiole), which is required 

 for reproduction. The smallest portion of such plants as begonias, 

 gloxinias, &c. will form an independent plant. 



Leaves of the orange, the hoya, the aucuba, ficus elasticus, the 

 clianthus, the common laurel, and a few more, have been occasionally 

 rooted, but more as matter of curiosity than for the purpose of increase. 



Propagation by the leaves of bulbs has been successfully effected by 

 the Hon. and Rev. W. Herbert, who first tried it, in 1809, by setting 

 a cutting of a leaf of a Cape Ornithogalum. " The leaf was cut off 

 just below the surface of the earth in an early stage of its growth, 

 before the flower-stalk had begun to rise ; and it was set in the earth, 

 near the edge of the pot in which the mother plant was growing, and 

 so left to its fate. The leaf continued quite fresh, and on examination 

 (while the bulb was flowering) a number of young bulbs and radical 

 fibres were found adhering to it. They appeared to have been formed 

 by the return of the sap which had nourished the leaf. Thereupon 

 two or three more leaves were taken off and placed in like situations ; 

 but they turned yellow, and died without producing any bulbs. It 



