Mottier—The Embryology of some Anomalous Dicotyledons . 459 
changes demanded by the theory. The writer feels that a detailed state- 
ment explanatory of his view would far exceed the purpose of this paper, 
and he prefers to let the matter stand at present with the above expression 
of his opinion. 
An argument in favour of the monophyletic origin of the Angiosperms 
has also been advanced by Miss Sargant (’ 03 ), but this observer considers 
the Dicotyledons as the more primitive stock from which the Monocotyle- 
dons have been derived, suggesting that the anomalous character of certain 
dicotyledonous embryos indicates the probable line of transition. Miss 
Sargant approaches the subject from the standpoint of the anatomy of 
seedlings, examining into the anatomical details of a large number of species, 
chiefly of the Liliaceae, and bringing the great mass of details together 
in a very careful and praiseworthy manner. 
Using Anemarrhena as a type, she finds two opposed vascular bundles 
in the terminal cotyledon. These extend down into the hypocotyl, where 
each divides, and the four plerome-strands thus formed are continuous with 
those of the tetrarch primary root. This behaviour of the bundles suggests, 
it is pointed out, that the single cotyledon of Anemarrhena is the homologue 
of two, which were separate in some dicotyledonous ancestor. It is further 
suggested that Eranthis hiemalis , one of the Ranunculaceae, may be 
illustrative of such an ancestor. 
A summary of the views of Coulter and Chamberlain in regard to the 
phylogeny of the Angiosperms is expressed by these authors (Morphology 
of Angiosperms, pp. 287, a88) as follows : — ‘ The Monocotyledons and 
Dicotyledons represent two independent lines derived directly from Pterido- 
phyte stock, probably from the Filicales. At the same time, the arguments 
in favour of the monophyletic origin of Angiosperms are strong ; and if 
this view be accepted, the derivation of Monocotyledons from primitive 
Dicotyledons seems to rest on stronger evidence than the reverse relation- 
ship. It must also be said that the Gymnosperm origin of Angiosperms 
is not to be discredited so much now as formerly.’ 
With the brief statement of the two views concerning the relative 
antiquity of Monocotyledons and Dicotyledons, under the assumption 
of a monophyletic origin, we are now prepared to examine more directly 
the evidence furnished by the embryology of anomalous Dicotyledons 
in the light of recent investigations. In basing conclusions upon morpho- 
logical data, indeed the most reliable of all, the first requisite is to determine 
whether the structures dealt with represent primitive or derived character- 
istics, as it is upon this point, of course, that observers will be found to differ 
most, especially in the presence of a few isolated facts. With a detailed 
knowledge of only a few anomalous Dicotyledons, observers were quick 
to regard this character as primitive, and consequently conclusions were 
easily reached. With the crescent-shaped primordium of the cotyledons as 
