Young Plant of Macrozamia Fraseri. 
569 
Text-fig. i. Transverse section of protostele in hypocotyl of young seedling, x 1 20. 
X. — xylem ; Ph. = phloem ; Pc. = pericyclic fibres. 
(e) Transition. The course of the leaf-traces 
and the transition phenomena agree very closely 
in all the seedlings studied, and are perhaps best 
explained by reference to one particular case. 
In a seedling in which germination has 
reached the stage shown in Text-fig. 2, three 
leaf primordia are to be distinguished. The 
first plumular leaf contains, at its junction with 
the stem, six mesarch bundles, arranged in an 
open arc (Text-fig. 3, A, L^-L-£). These soon 
reduce, by the fusion of two, to five, and this 
number continues throughout its petiole, the 
traces becoming exarch towards its distal end. 
Just below the insertion of the first pinna, these 
five entirely exarch traces are reduced to four 
by the fusion of the second and fourth anteriorly 
to the third and central trace. Text-fig. 2. Seedling of Macro- 
. zanna Frasen. Somewhat reduced 
In the second leaf of the plumular bud nine size. Ap. = Apogeotropic root. 
