350 The British Association at Birmingham. 
interpretation of Hanstein’s observations is that the single cotyledon 
of Monocotyledons is equivalent to the pair found in Dicotyledons : 
this would imply that Dicotyledons were derived from an ancestor 
with one cotyledon, apparently terminal, which gave rise to the 
existing pair by a process of splitting ; but other interpretations 
are possible, and the terminal hypothesis received a shock when 
Solms-Laubach discovered that in certain Monocotyledons the 
single cotyledon is lateral from the first. The comparative 
antiquity of Monocotyledons and Dicotyledons has been one of the 
first questions raised by the study of seedling anatomy, and it is 
remarkable that both the hypotheses founded on work of this kind 
assert the greater antiquity of the dicotyledonous form ; but if the 
cotyledonary member of Monocotyledons is derived from one or 
both cotyledons of an ancestral pair, it cannot be considered as 
terminal. Thus the evidence of seedling anatomy bids fair to settle 
both these problems, and probably others of the same kind. 
Though the progress of botanical embryology has been here 
treated from the morphological side only, it is clear that every 
department of botany must deal with the immature plants as well 
as with the adult form. For instance, the struggle for existence 
between two species in any particular locality must be profoundly 
affected by the characters of their seedlings. If one species should 
gain a decided advantage over the other early in life, the vanquished 
species may never live to set seed, and may thus disappear from the 
neighbourhood in the first generation. This is an extreme case to 
show the importance of considering seedling structure in problems 
of ecology and distribution. The internal structure of seedlings is 
certainly a department of vegetable anatomy, just as their adaptation 
to the conditions of life is a department of vegetable physiology. 
That the connection between embryology and systematic botany 
must be equally close seems at first sight to be beyond dispute, 
but the exact nature of that connection is as yet undetermined. 
Certain features of the embryo are included among the characters 
used by systematists, but on the whole the latter have dealt 
exclusively with the adult plant, the embryo itself having been 
treated rather as a portion of the seed than as an individual. We 
need not be surprised if conclusions drawn from the new embryo- 
logy—that is, the embryology which includes internal characters 
as well as external—sometimes appear to conflict with the results 
of systematic botany, and it does not necessarily follow that 
embryological evidence is of no systematic value. The fault may 
lie with the embryologists who, being human, do occasionally 
misinterpret their facts, or possibly the natural system may need 
some modification in the light of new knowledge. When both 
explanations have failed to account for the discrepancy in a number 
of cases, we may be forced to give up looking for phylogenetic results 
from embryology. 
Morphological and Pal^eobotanical Papers. 
Prof. G. S. West read two papers on Green Algae. In a 
paper on the structure, life-history and systematic position of the 
genus Microspora , he remarked that species of Microspora were 
among the commonest and most widely distributed of British fresh¬ 
water Algae, gave an account of the nature of the chromatophores 
