veel gd) go se ce ae See te See Us os ee eed ee 
Peete 
1914] . MANEVAL—MAGNOLIACEAE 27 
and within this a stony one, both developed from the outer integu- 
ment, and a thin inner one from the inner integument. 
6. The flowers of both species differ from the euanthostrobilus 
of ARBER and PARKIN only in having anatropous ovules and two- 
seeded carpels. 
7. In Liriodendron the seedling possesses in the cotyledons 
and upper part of the hypocotyl the structure generally found 
associated with tetrarch roots, but the root is diarch. 
8. All Magnoliaceae possess certain common anatomical char- 
acters, while others are peculiar to particular groups. The 
bundles in the petioles and peduncles of Liriodendron and various 
species of Magnolia are somewhat scattered, a feature the inter- 
pretations of which vary. 
9g. Porscn’s archegonium theory gives no suggestion as to 
what type of angiospermous embryo sac is primitive. 
to. A consideration of all available evidence in the light of 
present theories very strongly favors the conclusion that the 
ordinary 8-nucleate type of angiospermous embryo sac is the most 
primitive. But in view of its wide distribution among all groups 
_ of angiosperms, its occurrence either among the Magnoliaceae or 
in any other family is no evidence of the primitiveness of that 
family. 
11. Angiosperms are believed to be monophyletic, especially 
on account of the uniformity in the development and mature con- 
dition of the gametophytes, and because of similarity in seedling 
structure of monocotyledons and dicotyledons. 
12. The view that dicotyledons have been derived from mono- 
cotyledons, as advanced by WorRSDELL, rests too largely on assump- 
tion. 
13. The theory that monocotyledons originated from dicoty- 
ledons is supported by evidence from gametophytic development 
and anatomical structure of seedlings and mature plants, as well 
as by indications that primitive angiosperms possessed a cambium 
and were dicotyledonous, and by the conclusion that the peculiari- 
ties of anomalous dicotyledons are seeoneary: The iiportent 
_ differences between tyledons and licot on 
_ the one hand, and ordinary dicotyledons on the other, are believed 
