the Young Epicotyl in some Ranalean Forms . 159 
collateral strands of varying sizes. There would appear to be no interfasci- 
cular cambium. 
The young stem, as found in the epicotyl of seedlings, has a much 
more regular ring of bundles connected, particularly in the perennial 
species, by a strongly developed ring of cambium. The number of strands 
supplied to the stele from each leaf is usually three. Those of the first two 
leaves may be two or one, and, according to M. Lenfant , 1 in the adult plant 
of annual species the number of strands is augmented by others appearing 
between the median strands and the laterals. 
D. for mo sum. This is a perennial species. The seedling has a five-fid 
leaf and the cotyledons show a tendency to bifurcate. At a very early age 
the hypocotyl shows a tuberous swelling. A short cotyledonary tube is 
present. The base of each foliage leaf also completely enfolds all younger 
structures. Near the point of insertion of the petiole the leaf-trace strands 
are three in number and cambial division has taken place within them. 
The three strands enter the ring of bundles at different points and, at the 
same level, some of the strands within the vascular cylinder fuse so that, at 
the age examined, the number of strands in the internode remains about 
five. Exactly which strands unite varies in different individuals and at 
different nodes. The inception of a complete cambial ring is at about the 
level of the node of the youngest fully expanded foliage leaf. The cotyle- 
dons each contain a double bundle, but no laterals are present in the petiolar 
region (see Thomas, loc. cit.). The double bundles join the ring at the 
same level as the median strand from the first foliage leaf, the laterals of 
which were inserted at a higher level. In the upper part of this ‘ double 
node ’ are present three strands derived from the second and subsequent 
leaves. These arrange themselves two on one side and one on the other of 
the plane passing through the cotyledons. The lateral strands from the 
first leaf fuse with the single strand mentioned above before the central 
portion enters the ring, so that the appearance of three strands on either 
side of the cotyledonary plane is lost because, though present, they unite at 
different levels. 
The strands on the other side fuse below the cotyledonary plane, and 
the two plumular bundles thus formed pass down the hypocotyl, decreasing 
in bulk as the lower levels are reached. The cotyledonary strands have 
become arranged in the form of a diarch root so that these plumular 
bundles form the customary wings to. the diarch plate. 
D. occidental. The first two foliage leaves, though of different ages, 
are practically opposite and at right angles to the cotyledons. This feature 
is of fairly frequent occurrence among the seedlings of Ranunculaceae, but 
in this case it is correlated with a similar anatomical arrangement. The 
first two foliage leaves have a single strand, instead of the usual three, and 
1 Loc. cit., p. 44. 
