152 Blackburn.— On the Vascular Anatomy of 
the Nymphaeaceae in his investigation of the development of polystely in 
this family. 
In view of the great interest attaching to the Ranales on general 
grounds, 1 and to the Ranunculaceae in particular through the possession of 
the tubular type of stele to which Professor Jeffrey 2 attaches so much 
importance, it was suggested that a comparative investigation of Ranalean 
plumular anatomy in its early stages could hardly fail to yield results of 
some interest. A nucleus of material was handed over to the writer by 
Dr. Thomas, and has been supplemented by seedlings raised in the Botany 
garden of Bedford College, and in the case of many of the British species 
by those obtained in the field. 
Owing to difficulties in obtaining adequate material for a full study of 
the other families, Ranunculaceae has received the most attention. 
The axes of seedlings bearing from one to five expanded foliage leaves, 
in addition to the cotyledons, were microtomed from the stem apex to the 
upper part of the hypocotyl. 
The seedling morphology shows a number of general features, one or 
more of which may be departed from in individual cases, though on the 
whole they are very constant throughout the group. 
The first few internodes are relatively short, and the phyllotaxis is two- 
fifths. The cotyledons are epigeal and, where the first internode is specially 
short, the first two foliage leaves tend to be opposite and at right angles to 
the cotyledons. A cotyledonary tube is frequently found. 
With the exception of the very specialized Nymphaeaceae 3 the 
divergence from the type just described is in very limited and definite 
directions : 
(a) In Calycanthus and in some species of Clematis the early foliage 
leaves are opposite and decussate, and in Anona the phyllotaxis is one-half. 
(b) Hypogeal germination is found in certain large-seeded forms. It 
occurs throughout Lauraceae and Anonaceae and in certain species of 
Ranunculaceae, notably Anemone nemorosa and some species of Paeonia and 
Clematis (see Text-figs. 3 and 9). 
(e) The cotyledonary tube varies in extent. It is practically absent in 
Thalictrum , but it is well marked in Anemone fulgens , Podophyllum emodi , 
and Eranthus hiemalis (see Text-fig. 4). In Anemone apennina and 
Ranunculus Ficaria there is only one lobed cotyledonary member. 
As has been pointed out by Miss Sargant, 4 a tuberous swelling of the 
hypocotyl and accompanying suppression of the first few plumular internodes 
is frequently correlated with a long cotyledonary tube. Accordingly this 
1 See Arber, E. A. Newell, and Parkin, J. : On the Origin of Angiosperms. Journ. Linn. Soc., 
vol. xxxviii, 1907. 
2 See Jeffrey, loc. cit. 3 See G Wynne- Vaughan, loc. cit. 
4 Sargant, E. : A Theory of the Origin of Monocotyledons, &c. Ann. of Bot., vol. xvii, 
I9°3 } P- 77- 
