520 Worsdell ’ — The Morphology of the Monocotyledonous 
and the * peripheral zone ’ represents the cotyledon with its well-developed 
basal portion, and this single cotyledon, in the absence of a stem, must, of 
course ; be terminal to the whole embryo, as the earliest stages of develop- 
ment show it clearly to be. From all which it appears that Coulter’s 
position with regard to this matter is ambiguous and illogical. 
It having been deduced from all that has been set forth above that in 
Monocotyledons (all representatives of which have essentially the same 
type of embryo- and seedling-construction) the cotyledon is always single 
and terminal, the appearance of two lateral cotyledons in the Grass being 
due to the supervention of secondary modifications, the two remaining cases 
A 
Fig. 8. Agapanthus umbellatus (African Lily), a = outline of normal embryo ; a' = transverse 
section of cotyledon (c) and plumular leaf (pi). B = outline of dicotyledonous embryo. b' = trans- 
verse section of cotyledons and plumular leaves. (After Coulter and Land.) 
which Coulter and Miss Farrell marshal, in the endeavour to demonstrate 
their thesis of primitive dicotyledony in all Angiosperms, can be easily 
dealt with. I refer to the embryos of Cyrtanthns and Agapanthus in which 
two cotyledons occur. Both cases can be quite well explained as accentua- 
tions of the condition met with in the Dioscoreaceae and Commelynaceae 
in which the development of the sheathing portion of the cotyledon sets in 
at an early stage, and proceeds to an equal degree with that of the lamina. 
On the analogy of the Dicotyledons, if the orthodox view is held with 
regard to the morphology of the embryo of this class, then it is quite 
obvious that two cotyledons are present in these cases of Agapanthus and 
Cyrtanthus. And it is a most rare and interesting observation to have made 
that in these cases a second cotyledon is formed by the excessive develop- 
