1914] MANEVAL—MAGNOLIACEAE 7 
the different arrangements as correlated with the size of the leaves. 
WorsDELL (33) finds medullary bundles in the petioles of various 
species of Magnolia, and interprets these as reminiscences of a 
primitive, more scattered system in their ancestors. He believes 
also that the somewhat irregular system of bundles in the peduncle 
of Liriodendron and Magnolia indicates the same thing. If we 
accept the view that dicotyledons have been derived from mono- 
cotyledons, this explanation might seem more or less plausible; 
however, on the theory that monocotyledons are secondary, this 
interpretation could hardly be correct. 
Present theories concerning the primitiveness of various types 
of angiospermous embryo sac will now be discussed. According 
to the archegonium theory of Porscu (22), the 8-nucleate embryo 
sac is to be interpreted as the equivalent of two archegonia, a 
micropylar one represented by the egg apparatus, and a chalazal 
one represented by the three antipodals. Accepting this view, 
as has been pointed out by Brown (3), “we might conceive of 
the embryo sac of Peperomia as really composed of four sacs, each 
of which gives rise to one archegonium.” A similar explanation 
might hold also for certain other anomalous embryo sacs such as 
are found, for example, in the Pennaeaceae. Porscu, however, 
in his paper considers only the 8-nucleate type. 
This theory has been criticized from various standpoints. In 
the gymnosperms, for instance (3), in all species that form arche- 
gonia, the megaspore first produces a non-cellular stage of the 
gametophyte, and subsequently a cellular stage in all species that 
form archegonia; and it is in this cellular tissue that the archegonia 
are initiated and formed. So if we homologize the first two divisions 
of the ordinary angiospermous embryo sac: with the free nuclear 
divisions of the gymnospermous prothallus, the shifting of the 
archegonia from the cellular to the non-cellular stage of the pro- 
thallus must be explained. 
ERNst (9) admits that the archegonium theory would be 
sehr bestechend if within the 8-nucleate embryo sac the two groups 
of nuclei were always of nearly the same form. The numerous 
variations from the “‘normal’’ type, not only in the form of the 
egg apparatus and of the antipodal apparatus, but also in the 
