657 
certain Orders of the Ranales. 
a greater or less extent. As the more external of these bundles began 
to form themselves into a ring, and this latter began to increase the extent 
of its tissues to an ever-increasing degree by means of secondary thickening, 
this would tend to induce a degradation and eventual disappearance of the 
cambium of the medullary bundles and, finally, of the bundles themselves. 
RANUNCULACEAE. 
The grandifoliate habit is strongly represented in this order. They 
are mostly plants with a squat vegetative stem bearing large leaves. Some, 
as R. Ficaria and E ran this, are typical geophytes having no aerial, leafy 
stem, but merely peduncles terminating in a flower ; most, however, seem 
rising out of the squat habit, inasmuch as they produce a rather short, and, 
often, unbranched leafy stem, which, however, soon produces flowers, as 
in Delphinium . The members of this order bear a close resemblance 
to Monocotyledons, not only in their vascular anatomy but in their habit 
and the structure of their flowers. But they appear to be less specialized 
and reduced than most Monocotyledons of the present day, and are probably 
in several ways and on the whole more primitive. It is on account of the 
primitive floral structure that I regard the prevailing grandifoliate or sub- 
grandifoliate habit of these plants as also primitive. 
Anemone japonica , Sieb. & Zucc. 
I will take this plant as a type from this order of plants retaining 
the, to my mind, primitive scattered or medullary bundle-system. 
Leaf'. In the typical part of the petiole, which is more or less 
cylindric, the bundle-system is radio-symmetrical ; it consists of four ranks 
of bundles, of which those of the two outermost ranks are, many of them, 
situated at the same tangential level, there being, as so often happens, some 
irregularity in this respect. 
Several of the small outermost bundles are rudimentary, possessing 
either phloem and a sclerotic arc only, or only the latter, their xylem being 
quite absent. These same rudimentary bundles occur in Monocotyledonous 
stems and leaves. The innermost rank is represented by a single large 
bundle occupying a perfectly central position. The xylem is very V-shaped> 
subtending a circular phloem. This, then, is the same structure which pre- 
vails unmodified in the aerial stem. In the sheathing base of the petiole 
this scattered system changes gradually into that of the arc, and this takes 
place by the bundles on the ventral side passing across and fusing with 
those on the dorsal side, or assuming a position between them, at the same 
time revolving on their axes through i8o°, while all the small rudimentary 
bundles and a few of the larger ones gradually die out completely or 
become more and more rudimentary towards the base of the leaf. 
Aerial stem : This must be regarded as the typical and least modified 
