33° BOTANICAL GAZETTE [MAY 
the level dividing the axis of the embryo from its cotyledon. 
But as the cotyledon develops it does not appear terminal as it 
commonly does among true monocotyledons. The plumule soon 
comes to lie in a straight line with the axis, and the cotyledon is 
a hollowed structure which partly surrounds it. Indeed, the 
whole embryo at this age closely resembles that of Tamus as 
described by Solms-Laubach, in which the cotyledon appears 
lateral from the first (figs. 4, 5, 6, p. 340). 
Hegelmaier indeed describes a single abnormal embryo of 
Carum Bulbocastanum in which the lower lip of the usually lateral 
cleft containing the plumule attains some size, and he interprets 
this structure as the rudiment of a second cotyledon. Little 
weight can be attached to an isolated case of this kind. We do 
not even know whether the lump of tissue he figures would have 
become a leaf-like member. This is the only ground for consid- 
ering the absence of a second cotyledon in any pseudo-mono- 
cotyledon as due to its early abortion. We may therefore fairly 
Say that the comparative study of the young embryo in the 
genera Ranunculus, Corydalis, and Carum does not indicate the 
process by which a species within those genera has come to 
possess a single cotyledon where its ancestor had two. 
The history of the embryo within the ovule and seed then 
throws no light on the comparatively simple problem of the deri- 
vation of such forms as Corydalis cava, Ranunculus Ficaria, ot 
Carum Bulbocastanum from the ancestral Corydalis, Ranunculus, 
or Carum. This consideration casts great doubt on the value of 
similar evidence when we attempt the harder task of tracing the 
origin of monocotyledons from an ancestor far more remote. 
To sum up, research conducted on the three lines hitherto 
considered does not afford evidence of any great value in favor 
of the superior antiquity of monocotyledons. On the other hand, 
it does not so far support the opposing claims of dicotyledons. 
EVIDENCE FOR THE PRIMITIVE DICOTYLEDON. 
Two observers, M. Quéva and Professor E. C. Jeffrey, have 
recently appealed to anatomical evidence of a kind hitherto neg- 
lected. M. Quéva has made a careful anatomical study of 
