THE AUSTRALIAN. NATURALIST. 149 
REPRODUCTION OF PLANTS FROM LEAVES. 
By A. A. Hamtton. 
A peculiar form of vegetative reproduction—a habit which has 
suggested to the author the generie name for the plant—is a 
normal condition in Bryophyllum calycinum, a member of the 
“House-leek” family (Crassulaceae), indigenous in the Malayan 
Archipelago, and widely cultivated as an ornamental garden 
plant. When the fleshy leaves commence to decay and foll 
from the plant, adventitious shoots emerge from the crenatures 
ot the leaf margin. The specimens of leaves exhibited were 
placed between sheets of paper in the customary manner for 
drying, and it will be noted that the shoots, which emanated 
from the leaves during the process, are blanched (etiolated) as 
a result of growing in the dark. In a paper, “The Reaction of 
Leaves to Traumatic Stimulation” (Wounding) (Ann. of Bot., 
Vol. 15, p. 533), the authors note that the cut-off leaves of the 
Oleander (Nerium Oleander) invariably put out  vigerous 
crops of adventitious roots from the stump of the leaf-stalk 
if kept in the dark and supplied with water. The capacity for 
the production of adventitious buds on their leaves is inherent 
in several herbaceous garden plants, e.g., Begonias, Gesneras, 
&c., and certain Ferns, and is occasionally used by the hortieul- 
turist to propagate the species. The detached leaf is mutilated 
to stimulate growth and: pegged down or laid, lightly covered, 
on damp said. HK. J. Salisbury (Ann. of Bott., Vol. 29, p. 
309) figures the occurrence of buds arising from the leaves of 
several species of the “Sundew” (Drosera), which developed 
into independent plants upon the fallen leaves. The Sundews, 
which were taken from a pond, developed this abnormality 
under cultivation in a greenhouse. Probably the best known 
example of this form of vegetative reproduction occurs in the 
Prickly Pear (Opuntia). In the Gard. Chron. for September, 
1888, p. 328, a figure is presented of a frnit of an Opuntia 
showing roots emitted from its base and_ shoots, representing 
segments of the stem (cladodes) arising from its apex, after the 
fall of the corolla and stamens. 
In a note on Non-sexual Propogation in Opuntia (Bot. Ga- 
zette. V. 31. p. 127). GC. E. Preston, of Harvard University, 
draws attention to Opuntia arbuscula, whose fruits, though 
produced in abundance, contain few fertile seeds. The heavily- 
Jaden branches bend over to the ground, and in this position 
