founded on the Structure of their Seedlings. 7 
and the intermediate forms which have led me to derive them 
from the Anemarrhena type. These facts will, I hope, go far to 
justify the preliminary assumption that the vascular symmetry 
of the seedling affords a new systematic character, which — at 
least among the Liliaceae — is often of value in indicating the 
historical connexion between genera. While on this subject 
I shall also describe more briefly some monocotyledonous 
seedlings outside the Liliaceae, and in particular those whose 
structure connects the group to which they belong with that 
family. 
In the second place, I intend to describe in detail the first- 
year seedling of Eranthis hiemalis , comparing its vascular 
structure with that of Nigella damascena , already well known 
through the descriptions of MM. Gerard, Dangeard, and 
Sterckx. From the other Ranunculaceous species which 
possess cotyledonary tubes, I have examined and shall shortly 
describe Anemone coronaria and a species of Delphinium , and 
for comparison with these exceptional forms I have chosen 
four species with distinct cotyledons from the same family. 
In conclusion, the seedling of Ranuncidus Ficaria will be 
fully described as a type in which the cotyledons are partly 
united by one margin only. 
These two chapters will complete the account of the 
evidence on which my theory is based. This evidence is 
obviously incomplete. The theory itself cannot be considered 
as proved in any sense. It is brought forward as a working 
hypothesis which I have found in practice to be suggestive 
and illuminating. But a theory of the origin of the mono- 
cotyledonous cotyledon is in fact a theory of the origin of 
Monocotyledons themselves, and therefore to the two chapters 
which contain my own observations on the comparative 
anatomy of seedlings I shall add a third dealing with the 
theoretical aspect of the subject. In this I shall try to show 
that the same habit of life which leads to the partial union of 
some dicotyledonous seed-leaves may in the past have pro- 
duced one or more distinct races with seed-leaves so completely 
united that they appear to form a single member. 
