It is
therefore a curious fact that in one of these 15 species, viz., M. Taurica
(and in a lesser degree in two others), leaves arising from young shoots,
produced on plants which had been cut down and kept in pots during the
winter in the green-house, slept like the leaves of a Trifolium, whilst the
leaves on the fully-grown branches on these same plants afterwards slept
normally like those of a Melilotus. If young shoots rising from the ground
may be considered as new individuals, partaking to a certain extent of the
nature of seedlings, then the peculiar manner in which their leaves slept
may be considered
[page 416]
as an embryological habit, probably the result of Melilotus being descended
from some form which slept like a Trifolium. This view is partially
supported by the leaves on old and young branches of another species, M.
Messanensis (not included in the above 15 species), always sleeping like
those of a Trifolium.
The first true leaf of Mimosa albida consists of a simple petiole, often
bearing three pairs of leaflets, all of which are of nearly equal size and
of the same shape: the second leaf differs widely from the first, and
resembles that on a mature plant (see Fig.
Pages:
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694