Syncotyly and Schizocotyly . 801 
that the Spadicifloreae are derived from Dicotyledons of the Piperalean 
alliance, we may agree that monocotyly has here arisen in the heterocotylous 
fashion, as illustrated by certain geophilous species of Peperomia } There 
remains the question of the origin of monocotyly in all the other Mono- 
cotyledonous orders, and here it appears that the theory of syncotyly has 
much to recommend it. 
On the side of the Dicotyledons a large number of species are known 
in which fusion of cotyledons for a greater or less distance has undoubtedly 
occurred, and is a constant feature of the seedlings. The theory of syncotyly, 
as expounded by Miss Sargant , 2 is largely based on the resemblances in 
anatomy between such normally syncotylous Ranunculaceae and Ane- 
marrhena asphodeloides among the Liliaceae. The syncotyly usually takes 
the form of the production of a long cotyledonary tube, through the base of 
which the plumule breaks ; but in Ranuncidus chius the fusion is along one 
margin only. 
In studying such anomalous Dicotyledons comparison can only be 
made with other related species with two seed-leaves. The advantage of 
an examination of teratological syncotyls lies in the facts that we can com- 
pare them with normal dicotyls of the same species, and that a series of 
degrees of syncotyly can be studied. Unfortunately the material is neces- 
sarily scanty, except in such a case as de Vries’s Helianthus annuus 
syncotylens , which throws a high percentage of syncotyls. The criticism 
that such abnormalities are of no significance will be dismissed by serious 
students of teratology. 
It is hoped that as time goes by it will be possible to obtain further 
examples of syncotyly to supplement the present account. Imperfect 
though this is, it throws a certain amount of light on the main problem. 
In the first place, syncotyly, when it occurs, is a symmetrical process, 
both cotyledons taking an equal part in the production of the single seed- 
leaf. The vascular system, as would be expected, is also symmetrical about 
the plane in which the fusion takes place, i. e. the intercotyledonary plane, 
though in no other. In Swainso?ia Cadelli the fusion has no marked effect 
on the vascular system. This is also the case apparently in Raiiuncidus 
chius , a normally syncotylous species, as compared with other Ranun- 
culaceae ; 3 but it is noteworthy that Ranunculus Ficaria , which Miss Sargant 
regards as a syncotyl, differs markedly from R. chius , the only other 
syncotylous species of the genus examined. In R. chius the two cotyledons 
each send a double bundle into the diarch root, the two cotyledonary 
systems being independent of one another. In R. Ficaria , on the other 
hand, the bilobed seed-leaf only sends one double bundle 4 into the root, this 
1 A. W. Hill (’06). 2 Sargant (’03), p. 66; and (’08). 3 Sargant (’03), p. 65. 
4 Some of Sterckx’s specimens also had lateral petiolar bundles in addition to the midrib 
(Sterckx (’99), p. 45). 
