r914] MANEVAL—MAGNOLIACEAE 15 
stems, hence the great importance of any evidence as to its presence 
among primitive angiosperms. That a true cambium develops 
in certain monocotyledons (Gloriosa, 23) is now well known; but 
especially significant is the fact that while the structure of the 
mature stem of monocotyledons and dicotyledons generally varies 
greatly, the primary structure of the dicotyledonous stem, which 
is the same in seedlings and mature plants, is also frequent in 
monocotyledonous seedlings. So in the light of this evidence and 
also of the fact that a cambium is usually present among living 
gymnosperms and extinct vascular cryptogams, and is universally 
present, so far as known, among extinct gymnosperms, the view 
that primitive angiosperms possessed a cambium seems well 
founded. 
The argument for most of Miss SARGANT’s other views cannot 
be included here, yet one other conclusion should be mentioned. 
Since among gymnosperms monocotyledoneus forms are unknown, 
and the dicotyledonous condition prevails, one would naturally 
presume that the embryo of primitive angiosperms was dicotyle- 
donous; besides, the embryological development of angiosperms 
points in the same direction. So the general conclusion is that 
monocotyledony is secondary, being the result of a fusion of two 
cotyledons. 
ARBER and PARKIN in discussing the origin of angiosperms 
hold “that monocotyledons branched off from the main angio- 
spermous line, that is, dicotyledons, at a very early period.” 
Since the embryo of Bennettites was dicotyledonous, they regard 
the Hemiangiospermae as dicotyledonous also, and so conclude 
that the monocotyledonous type is the less primitive one. In 
their opinion Miss SarGANT’s explanation of the monocotyledonous 
embryo is the best yet offered. They also recognize the need of 
accounting for the origin of the monocotyledonous habit. 
For a number of years the so-called anomalous dicotyledons 
have attracted students in the hope that knowledge of their 
embryos and anatomy would aid in solving phylogenetic problems. 
One of the general conclusions of such investigations is that the 
anomalous characters are secondary and not primitive features. 
Morrtrer (18), for example, says, “it is probably true without 
