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and hybridizing plants, made numerous experiments with the leaves 
and scales of plants of the lily tribe. He planted leaves cut off just 
below the surface of the soil, and they produced bulbs ; and by this 
means he was able to multiply some kinds of bulbs which did not wil¬ 
lingly produce offsetts. In other experiments without cutting off the 
leaves, he made an incision in the midrib just below the soil, in others 
just above, and so layered them. Young bulbs were formed on the edge 
of the cut above ground as well as below. He made cuttings of the 
stems of species of Lillium, which formed bulbs in the axils of the leaves ; 
he also obtained bulbs from scales. 
Neumann, a French gardener, the author of an excellent treatise on 
the propagation of plants, republished in the Gardener’s Chronicle of 
1845, also made numerous experiments with leaves, and he found that 
if the midrib of some leaves was lightly broken, and the leaf placed on 
the earth, a callus w'as formed at each fracture, which gave rise to roots. 
He cut a leaf of Theophrasta into two pieces, both of which emitted 
roots, formed buds, and produced plants. There is a great difference in 
the power of the detached leaves of different species of plants to form 
buds ; some will live two or three years without forming a bud. 
“ Can we possibly conceive,” says Lindley, “ anything better calculated 
to impress upon the mind the prodigious importance of these wonderful 
organs than a knowledge that they possess a vital energy of such force 
as to be able to produce young plants. Physiologists tell us that leaves 
breathe and perspire, but most people can see nothing of that, and pos¬ 
sibly disbelieve it. The regenerating power which a leaf possesses is 
one, however, palpable to the senses, and which all men can see; it, 
therefore, serves better than any other demonstration to impress upon 
the mind a conviction that it is an organ of the highest importance in 
the vegetable economy.” 
If buds and young plants can be produced by simple leaves, we might 
infer that there would be no great difficulty in propagating plants by- 
single mature leaves having buds already formed at their base. Many 
plants, difficult to propagate otherwise, are readily increased in this man¬ 
ner. This mode of propagating plants formed the subject of Andrew 
Knight’s last communication to the London Horticultural Society. He 
had raised in this manner the Camellia, Rhododendron, Magnolia, 
