200 ON THE ANATOMY OF SOME SAPOTACEOUS SEEDLINGS. 
- 
Fig.4. Transverse section of the root-stele 48:2 mm. below the node and about the middle of the 
swollen zone, to show further increase in number of metaxylem elements, formation of 
secondary xylem, and lignification of pith. 
4a. Transverse section of one of the vascular groups in fig. 4. : 
5. Transverse section of the root-stele 36 mm. below the node and at the upper end of the swollen 
zone, to show the forking of the metaxylem and the dying out of the secondary xylem and of 
the lignification of the pith. 
6. Transverse section of the hypocotyledonary stele 12:5 mm. below the node, to show the 
formation of two collateral vascular bundles from one root-bundle, with protoxylem between 
them. 
7. Transverse section at the node, to show the break up of the phloem-bands, 
7 a. Transverse section of one of the double bundles in fig. 7. Protoxylem is now internal. 
8. Transverse section a little higher in the node than fig. 7, to show the disappearance of the 
phloem from the cotyledonary plane. 
9. Transverse section of the node, to show the passing out of the two double bundles of the axis 
to the cotyledons, and the beginning of the formation of the axis of the stem from the 
remains of the phloem of the hypocotyl. On a smaller scale than figs. 2-8. 
9a. Transverse section of one of the vascular groups of fig. 9, to show the forking of the proto- 
xylem, 
10. Venation of one of the cotyledons and half of the axis. 
Bumelia tenax. Figs. 11-16. 
Fig. 11. Two seedlings of Bumelia tenax (ll a & 114), life-size, and the nodal region of another (11). 
x 2. 
Figs. 12-16. Diagrams of steles, to show the transition of seedling 11 a on approximately the same scale 
as figs. 2-8. 
Fig. 12, Transverse section of hexarch root-stele. 
12 a. Transverse section, about 2 mm, below node, of a primary and an accessory vascular strand 
from fig. 12. Both have exarch protoxylem. 
18. Transverse section of the tetrarch root-stele with two accessory vascular strands. A little 
higher than fig. 12. 
13a. Transverse section of the same two strands as those drawn in fig. 12 a, showing that the 
primary strand alone has exarch protoxylem. These are taken from fig. 13. 
14. Transverse section of the stele at the node with protoxylem no longer exarch, to show the 
forking of the aecessory strands. 
15. Transverse section of the axis of the hypocotyl and longitudinal section of the axis of the 
plumular bud, showing the accessory strands of one side of the stele bending laterally to the 
bud. 
16. The same at a slightly higher level, showing the accessory strands of the opposite side of the 
stele also bending laterally to the bud. 
7. Seedling of Chrysophyllum Roxburghii with swollen zone. x 1. 
8. Seedling of Mimusops Elengi with swollen zone. x 1. 
19, Seedling of Mimusops Kauki. x 1. 
ee 
