the Young Epicotyl in some Ranalean Forms. 175 
structure is slowly formed by approximation of phloem and xylem groups 
alternately as described by Dr. Thomas. 1 
Magnoltaceae. 
The vascular cylinder in the adult plant consists of a ring of collateral 
bundles connected by cambium and a large amount of secondary thickening. 
In Magnolia and Liriodendron there is a complete cylinder of bundles in 
the base of the petiole, 2 and the leaf-trace insertion is multilacunar. 3 
There is a ring of bundles in the seedling petiole, but they are reduced 
to three in the base of the petiole, whereas in the adult plant, according to 
Worsdell, 4 rearrangements take place largely in the cortex of the stem. 
This condition may be compared with what was found in the seedling of 
Decaisnea. 
Magnolia. Two species of this genus have been examined. The 
seedlings are large, with prac- 
tically sessile cotyledons, 
elongated internodes, and 
a phyllotaxis of two-fifths. 
The foliage leaves are large 
and ovate. 
M. acuminata. The 
petiole contains a ring of 
six bundles which reduce to 
three in a similar manner to 
that found in Decaisnea , but 
above the point of insertion 
of the leaf base. The second 
foliage leaf has completely 
enfolding stipules, whose two 
strands fuse on the side of 
the axis opposite the leaf insertion and join the ring there, making a minute 
fourth member to the trace. The stipules of the first leaf are not sheathing 
and contain no vascular strand. The ring of bundles in the axis 
is well marked and similar to that of Decaisnea. Secondary thickening 
begins at an early age (see Text-fig. 19). 
The cotyledons each contain a double bundle and two laterals. The 
adjacent laterals from opposite cotyledons fuse and the four bundles so 
formed enter four gaps in the plumular vascular cylinder. Thus a cylinder, 
1 Loc. cit., p. 709. 
2 Matsuda, S. : On the Anatomy of Magnoliaceae. Jour. Coll. Sci. Imp. Univ. Japan, vol. vi, 
1893-4. 
3 Sinnott : loc. cit., p. 312. 
4 Loc. cit., p. 666. 
