194 MISS WINIFRED SMITH ON THE ANATOMY 
It is much more common to find the vascular groups arranged at the node as in 
fig. 14—i. e., with no accessory bundle between the groups destined for the same coty- 
ledons, but a lateral one on each side corresponding to the plane of separation of the 
cotyledons. On the whole, the changes in the relative position of the metaxylem and 
protoxylem of the primary bundles, which take place in the transition from root to stem, 
follow the same sequence as those described in Payena Leerii. It is noticeable here, 
however, that the protoxylem of the regions above the root is always isolated in a little 
oasis of parenchyma and separated by it from the metaxylem on each side of it, and 
external to it, and from the lignified parenchyma internal to it (fig. 14), almost suggesting 
mesarch structure. 
I think that the differences between the vascular features of Payena Leerii and those 
of Bumelia tenax may perhaps be classed as adaptive or correlative. The smallness of 
the cotyledons in the latter, and the absence of reserve food-material elsewhere, throws 
the seedling early on its own resources; hence the rapid growth and early development 
of the plumular leaves, creating a demand to which the plant replies by the formation 
of accessory vascular strands in the root. I was unfortunately unable to compare the 
connection between hypocotyl and first internode in the two plants, as I had no 
specimen of Payena Leerii in which the shoot had developed. 
Fig. 5. Fig. 6. Fig. 7. 
pu vv 
LE e 
SPO 4Y b S As 
Root. Node, and 2:5 em. below. Base of cotyledon. 
S4 ADV 
Palaquium petiolare.—B. 
The course of the two double bundles in the cotyledons differs from that pursued in 
Payena Leerii. The double bundles diverge from one another, and the halves of the 
said bundles separate. A continuous branching goes on, and branches are given off not 
only towards the periphery but also towards the centre of the cotyledon. There is no 
fusion of traces and no distinct midrib, though one trace does, near the leaf-tip, occupy 
a nearly median position. Here fourteen veins were cut in transverse section. 
In Palaquium (— Dichopsis) petiolare we meet with a slightly different type from 
those of Payena Leerii and Bumelia tenax, a type varying in anatomy even within the 
aspen I had no seeds of this plant and only three seedlings. The cotyledons have a 
very short petiole and are hemispherical in shape. They go probably hypogeal, for 
they are very large and heavy and the shoot develops early. They show no internal 
