704 Thomas . — Seedling Anatomy of 
separated by parenchyma. Thus the two phloem groups are separated 
from the somewhat distorted diarch plate by parenchymatous cells. In the 
middle line, however, of these cells, at right angles to the plate, there is to 
be found one row of secondary xylem elements, giving a curious tetrarch 
appearance. (Cf. E ran this.) 
Anemone apennina is a pseudo-monocotyledonous form in which the 
single cotyledonary member has a long petiolar region, bearing a more or 
less bifid blade. The root has the customary diarch structure ; this 
structure is not only found throughout the hypocotyl, but also above the 
cotyledonary node in the lower part of the cotyledonary petiole. Thus the 
transition takes place wholly in the cotyledon, and more or less in the region 
marked by a collet (Text-fig. 5), half-way between blade and insertion. 
This species will be more fully described in a subsequent paper. 
The twelve species of Anemone examined indicate the prevalence of 
cotyledonary tubes within the genus and the tendency to form tubers. 
A. apennina is extreme in both characters. The cotyledonary member 
appears to be absolutely single, and none of the individuals examined show 
the bisymmetrical anatomy figured by Sterckx. 1 
Twelve species of the genus Ranunctdus have been examined. With 
the exception of R . Ficaria , which is a pseudo-Monocotyledon and wholly 
peculiar, the species do not differ from one another in any important 
respect, and are generally characterized by the sharp angle of entry of the 
cotyledon strands, rearrangements occurring at the entry, so that a diarch 
structure is met with just below the node. Secondary roots are produced 
almost at the node, and in some species, e. g. in R. sceleratus , there is 
a tendency for the primary root to abort as in Monocotyledons. Most of 
the species have a slight cotyledonary tube, and some form tubers. 
Ranuncidus acris , R. gramineus , R. parviflorus show very perfectly 
the features of the genus. They are slender forms, but with a tendency to 
the suppression of internodes. The small diarch root structure is found 
just below the cotyledonary node. As the strands pass from the hypocotyl 
into the base of the cotyledonary tube, they usually become single and 
collateral. Each is continued into the free portion of a cotyledon as its 
single central collateral strand, which only gives off laterals in the lamina 
(Text-figs. 6 and 7). 
R. bidbosus , R. arvensis , R. auricomus , and R. repens are quite similar, 
and call for no comment. 
R. hederacens shows great development of secondary roots at the node 
(Text-fig. 8). 
R. sceleratus has not only plentiful secondary roots at the node, but 
the primary root dies out at an early age. 
1 Sterckx, R. : Recherches anatomiqnes sur Tembryon et les plantules dans la famille des 
Renonculacees. Mem. Soc. roy. Sci., Liege, ser. iii, t. ii, 1900. 
