Seedling Structure of certain Centrospermae . 185 
similar to that in the leaves of the mature plant, and may be understood best 
by tracing the strands outwards from the cotyledonary node (Diagram 3, 
Fig. 6). A single trace (c. 1) leaves the node and branches into three 
portions ; of these the median strand (c. 2) divides up and supplies the free 
leaf-tip, whilst the two lateral strands (c. 3 and c. 4) curve outwards and pass 
downwards, their branches supplying the cotyledonary sheath and ultimately 
ending blindly in the aqueous tissue. 
Tracing the strands downwards, in order to follow the transition, 
a section through the united cotyledons (Diagram 3, Fig. 1) shows numerous 
bundles which are the branches of the central cotyledonary strands. Con- 
sidering one side only, these bundles unite, as the sections are traced down- 
wards, to form one strand (c. 2) which, at the node, is joined by the lateral 
trunks c. 3 and c. 4. Thus from each seed-leaf one end arch collateral bundle 
