Bowenio spectahilis , Hook . f. 477 
far as the supply of material would allow, comparison was 
made with younger seedlings : in the cases indicated the 
sections figured were taken from younger plants. 
The Seed. (Fig. 1, s.) 
The embryo occupies an axile position in a copious starchy 
endosperm whose consistency is compact and almost brittle. 
The testa is horny and thin. In germination the cotyledons 
remain within the. endosperm and function as an absorbent 
organ. The depletion of the endosperm is a process of 
long duration ; in some of the oldest seedlings examined 
the endosperm was by no means all exhausted. At their 
distal ends the two cotyledons are united into a single 
club-shaped body which projects into the endosperm (Fig. 
3, /. cot.). A transverse section through this region shows 
a well-marked line of separation between the two portions 
of the united cotyledons. The proximal portions and the 
petioles are free. 
The cotyledons are bounded by a definite epithelial layer 
composed of cells which are elongated in a radial direction, 
and are rather smaller than the ordinary mesophyll-cells. 
These cells are filled with dense protoplasmic contents and 
have large nuclei. The mesophyll-tissue of the cotyledon 
is composed of large parenchymatous cells of a uniform size. 
A single leaf-trace in the stem divides to form about four 
separate bundles which enter the cotyledons. One or more 
of these may divide again, so that from four to seven distinct 
bundles, arranged in an arc, are found in each cotyledon. The 
bundles are orientated normally, the phloem being on the 
dorsal side of the xylem. The larger quantity of the xylem 
is centripetal, a considerable number of centrifugal elements 
being also developed (Fig. 4). The centripetal xylem is 
usually somewhat extended in a tangential direction, beyond 
the general contour of the bundle : one or two elements on 
the flanks of this portion of the bundle are elongated tan- 
gentially and show characteristic reticulate markings on their 
