802 
Compton . — An Anatomical Study of 
being derived equally from the two similar lobes of the seed-leaf and from 
its midrib ; the second xylem pole of the diarch root is plumular. The 
conclusion seems to be that the single seed-leaf of R. Ficaria represents 
a single cotyledon ; the fact that it is bilobed cannot by itself be held to 
indicate syncotyly, for this phenomenon normally occurs in both cotyledons 
of other species of dicotyls, though there is nothing to suggest their 
derivation from tetracotylous ancestors (e.g. Raphanus sativus , Eucalyptus 
orientalis , Eschscholtzia calif ornicap Schizopetalon spp., &c.). Moreover, the 
venation of the seed-leaf of R. Ficaria , on which Sterckx lays such stress as 
being distinct from that of the forked cotyledon of Raphanus sativus , is 
not characteristic of syncotyls ; indeed, it can be closely paralleled among 
hemitri- and hemitetracotyls such as those of Cannabis sativa and other 
species described in another part of the present paper. The presence of 
a median Commissural nerve in the great majority of the seedlings of 
R. Ficaria which I have examined and some of those figured is no argument 
for either theory, for this may occur in both syncotyls 2 and in schizocotyls ; 3 
but in specimens of R. Ficaria , in which there is scarcely any lobing, the 
midrib is conspicuous and the venation is on the same general plan as that 
of the foliage leaves, allowing for differences of shape. There is nothing in 
the embryogeny of R. Ficaria to indicate which method of reduction was 
adopted; and, as a matter of fact, Hegelmaier 4 and Schmid 5 assume the 
heterocotylous, Sterckx G the syncotylous theory, without entertaining the 
other alternative. 
On the whole the tendency of the evidence seems to be in favour of the 
view that the seed-leaf of R. Ficaria represents a single cotyledon ; whether 
the second ancestral cotyledon has been completely aborted, as contem- 
plated by previous authors, or whether it has been retarded in development 
and now appears as the first foliage leaf 7 are subsidiary questions which 
cannot be considered further here. 
If we therefore omit R. Ficaria from the list of normal syncotyls we 
are left with two species only, in which there is pronounced cotyledonary 
fusion along one edge alone. These are Ranunculus chins , of which Miss 
Sargant saw three specimens ; and perhaps Anemone apennina , as to 
which, however, the contradictory statements of Sterckx 8 leave the facts 
in some doubt. The production of a long cotyledonary tube and its 
rupture by the plumule are frequent, and may perhaps be compared to 
1 Kerner and Oliver (’02), p. 621. 2 Winkler (’84), p. 39. 
3 e. g. in some specimens of Cannabis sativa. 
4 Hegelmaier (78). 5 Schmid (’02), p. 21 1. 6 Sterckx (’99), p. 42. 
7 The second alternative is supported by the facts that (i) 180 0 separates seed-leaf and first 
foliage leaf — an argument used by Miss Sargant (’08, p. 157) for syncotyly. (ii) The first foliage 
leaf trace forms one protoxylem pole of the diarch root, the seed-leaf trace forming the other, (iii) 
Retardation of development is a marked feature of the embryogeny of R. Ficaria, as of the other 
pseudo-monocotyledons Corydalis cava and Carum Bnlbocastanum. 
8 Sterckx (’99), pp. 34, 80. 
