64 PROLIFEROUS LEAVES, AND NOTES THEREON. 
3. The process is, however, greatly aided and accelerated by 
artificial means; by keeping them on wet surfaces in a warm 
room, covered up in damp moss or in a bottle, which, when 
carried in the pocket has twice at least induced the secondary 
plants to commence germinating, and thus exhibited three 
generations at once: twelve little plants were exhibited on a 
single terminal leaflet at the British Association, and much 
admired by Pror. Batrour; since which time eighteen if not 
nineteen were raised by making ten transverse sections of a 
very large leaflet, which were successfully dried and exhibited 
at our Conversazione, 1875. 
4, As to the process, the radicle first appears on the upper 
side of the leaflet as a silver thread, and the plumule commences 
as a tubercle, enclosed in a green vesicle which soon bursts like 
an eggshell. This is always on the median line, at the very 
base of the leaflet, and may or may not be followed by a series 
along the mid rib and other ribs; but never on the margin, as 
in Bryophyllum, though the ribs certainly do extend to the very 
edge. Pror. Batrour said it seemed as if every cell were capable 
of development, when he saw a leaf bristling with little germs. 
It is however very desirable that microscopists should examine 
the leaflets previous to germination, and ascertain whether the 
peripheral cells, which are never proliferous, differ sensibly from 
the rest, and especially from the basal which are always fertile. 
The history of “the cell” is not yet quite exhausted. 
5. No other British Plant has been induced by any coaxing 
or nursing, to act the part which this Cardamine performs, 
unaided, in all weathers except hard frost. Rootlets are given 
out freely by Watercress; and whole plants spring from sub- 
merged stems of Ranunculus flammula, and some others. 
Proliferous grasses and garlics are common; and we know the 
habit of one of the Polygonums, hence called viviparum. These, 
however, are all apart from the reproductive function of our leaf, 
pur et simple, without the slightest metamorphosis. Certain 
exotics as Pelargonium, Gloxinia, and Begonia, are raised, in 
