Ranales , Rhoeadales , and Rosales . 
701 
The Forms described. 
The species to be described in this paper form part of an investigation 
on seedling anatomy which has been proceeding for some years. It was 
begun in 1902 at the instigation of Mr. A. G. Tansley, and some of the work 
was carried on while acting as his research assistant. I take pleasure in 
expressing my extreme indebtedness to him for the very kind permission to 
include the work done at that period. 
Quite recently I have been greatly assisted in the matter of prepara- 
tions, &c., by my Demonstrator and former student, Miss A. J. Davey, B.Sc. 
Some of the data included have been taken from preparations made by 
Miss K. Blackburn, B.Sc., in connexion with another investigation now in 
progress. 
In all, some 150 species belonging to the cohorts Ranales, Rhoeadales, 
and Rosales have been examined, about half of which are Ranalean forms. 
Much of the material has been grown at Bedford College, a little at 
University College, while seedlings for this investigation were raised some 
years ago at University College, Reading, and also by Miss Strudwick at 
Cambridge. 
Ranales. 
More than seventy species have been examined, fifty-two of which 
are members of the Natural Order Ranunculaceae, seven of Berberidaceae, 
and one of Lardizabalaceae. In the Magnoliaceae six species have 
been examined, in the Calycanthaceae four, in Anonaceae two, and in 
Lauraceae two. 
The Ranunculaceae are very uniformly diarch ; the Magnoliaceae, 
Calycanthaceae, and Lauraceae are very largely tetrarch ; while the Berberi- 
daceae have tetrarch species. The Calycanthaceae present the most 
outstanding features, and show the rare Diagonal type in a very interesting 
form. 
Ranunculaceae. 
The Ranunculaceae are characterized by a tendency to form cotyle- 
donary tubes, which, as was noted by Darwin, seems to be associated with 
a tendency to form tubers. The lateral bundles of the cotyledon usually 
unite with the central high up, so that the base of the cotyledon shows 
only one bundle which is not usually markedly double. These bundles 
connect in many forms with the vascular system of the hypocotyl through 
a very sharp angle, rearrangements in the tissues taking place at the same 
time, so that the hypocotyl has a root-like structure from very near 
the node. 
