the Young Epicotyl in some Ranalean Forms. 153 
feature is found in all the species mentioned above with the exception of 
Anemone fulgens , and also in A. nemorosa (see Text- fig. 3). 
There is a corresponding general type of anatomy to which the 
majority of the seedlings described conform, though there are more variants 
from it than from the common type of morphology. 
Each foliage leaf contributes three traces to the axial vascular cylinder, 
which consists of a circle of separate collateral bundles anastomosing at the 
nodes. Early cambial activity connects the strands by secondary tissue. 
The number of primary bundles in subsequent internodes varies with the 
species, but in the lowest plumular internode there are usually six. These 
arrange themselves in groups of three on either side of the plane passing 
through the centre of the two cotyledons, which will be referred to as the 
cotyledonary plane. 
In general the cotyledons each contribute a double bundle, and thus 
a ring of strands is again completed (see Text-fig. 6). The three plumular 
and two half cotyledonary strands on each side then fuse, to give what often 
appears to be a single pair of collateral bundles, on the flanks of the diarch 
plate. This is usually formed quite high up in the hypocotyl, as described 
by Dr. Thomas. 1 
Some of the forms described possess independent lateral strands at the 
base of the cotyledons, and in the case, for instance, of Ranunculus arvensis 
the insertion of their traces is so remarkably like the insertion of the 
plumular traces in the same species, both as regards the number of strands 
from each cotyledon and their mode of entry, that one is tempted to 
suggest the possibility that this is the earlier condition for the cotyledons. 
The insertion of three strands from each cotyledon is in some cases con- 
nected with a tetrarch root, but in the plant referred to the lateral strands 
die out in the upper part of the hypocotyl. The anatomical similarity 
between leaf and cotyledon is here borne out by the existence of a series of 
leaf forms intermediate between the compound leaf of the adult plant and 
the simple ovate cotyledon. 
Just as there were forms whose morphology differed from the general 
ground plan, so the same or other forms may be aberrant in respect to 
anatomy. 
(a) Those forms of Clematis seedling whose foliage leaves are 
opposite show a reduction in the number of strands in the internode, four 
only being present. The insertion of the leaf-trace strands is also excep- 
tional. 
(b) In the species presenting both hypogeal and epigeal germination, 
as in Clematis, it is found that this feature has no anatomical consequences. 
(c) The tuberous habit causes anatomical modifications in several 
1 Thomas, E. N. : Seedling Anatomy of Ranales, Rhoeadales, and Rosales. Ann. of Bot., 
vol. xxviii, October, 1914. 
