founded on the Structure of their Seedlings. 5 
of Podophyllum from the allied order Berberidaceae is very 
well developed. 
Petiolar tubes are not confined to the Ranunculaceae and 
their near allies : they are found among the Oxalideae, 
Cucurbitaceae, Umbelliferae, Primulaceae, Polygonaceae, and 
probably careful search would discover them among seedlings 
of other families. 
In every case investigated they are accompanied by a 
thickened or at least much shortened hypocotyl. 
The anatomical structure of the petiolar tube and thickened 
hypocotyl of Eranthis , as described by M. Sterckx ( 38 , p. 57), 
early attracted my attention because it recalled that of 
Anemarrhena. I have therefore studied it in detail. 
The long petioles of Eranthis cotyledons are united into 
a narrow cylinder, which is hollow for the greater part of its 
length. The blades are distinct (PI. VI, Fig. 1). Through- 
out the length of this tube the blade of each cotyledon is 
represented by a single massive trace. These traces are con- 
tinued downwards through the tuberous hypocotyl into the 
primary root. The behaviour of the cotyledonary traces 
in the upper part of the tuber is precisely that of the coty- 
ledonary traces in Anemarrhena where they enter the tran- 
sitional region. This resemblance is maintained throughout 
the transition, until — near the base of the tuber — the four 
phloem groups of Eranthis unite in pairs to form two groups, 
instead of remaining distinct. The four protoxylem groups, 
however, can be observed for some time after the xylem plate 
is formed (PI. VII, Figs. 1 and 3) : in the end the two which 
are opposite the phloem groups disappear, leaving a diarch 
root-stele (PI. VII, Fig. 2). 
The anatomical resemblance between the seedlings of 
Eranthis and those of Anemarrhena cannot be mistaken 
when the features just described are represented in diagrams. 
Its theoretical importance, however, has been denied by 
Mr. Tansley ( 40 ), 
Three views are possible. The resemblance may be con- 
sidered as accidental : as the result of inheritance from a 
