BY JOHN SHIRI,EY AND C. A. LAiMBERT. 605 



3. Astpoxylon. — Type, Carronia multisepalea F.v.M., (Plate 

 Ixii., fig.6). — The stele consists of a central pith, composed of 

 very fine polygonal cells in which a few thick-walled ducts are 

 inserted at irregular intervals. Of wood and bast, there are 

 about thirty fibro-vascular bundles, each showing six to eight 

 large vessels, increasing in size, as usual, from the centre out- 

 wards. Bordering the pith in each, is a cluster of mainly spiral 

 vessels. Each medullary ray is well defined, and shows five to 

 eight rows of brick-shaped cells, parting at the circumferential 

 end to send, right and left, divisions round the separated bundles. 

 The bast-masses are oval and well defined. They are flanked 

 outwardly by older bast-tissues, now changed into sclerenchyma, 

 to be finally cast off with the outer bark. The different layers 

 of the bark are well defined, and the phelloderm assumes a wavy 

 outline, parallel to the outward curves of the various bundles. 



Lighter in colour than the rest of the stele, the medullary rays 

 present a stellate pattern on a freshly cut, transverse section of 

 the stem. 



4. Endophloia. — Bryonia laciniosa Linn. .(Plate lxiii.,fig.7).— 

 The development of the stem is apparently normal, but the 

 vascular bundles are bicollateral, having bast on both inner and 

 outer faces. The vessels of the xylem are unusually large for a 

 young stem in its second year of development. A large pad of 

 cork is seen on the side of the stem that has flattened by pressure 

 against the supporting plant. Very little pith is to be noted, 

 and the cells of the medullary rays are peculiarly large and broad. 

 There are signs of the production of interfascicular bast from 

 the sides of vascular bundles. 



5. Exoeyela. — Wistaria chinensis DC, (Plate Ixiii., fig.S). — 

 The medullary rays are exceedingly well defined, usually of 2-6 

 rows of radially elongated cells. At their outer extremities, the 

 cells, lying in the bast, are of larger size. The cambium-ring is 

 also clearly defined, and outside it are 6-8 ranks of thin-walled 

 bast-cells. The older bast-cells, pushed out towards the circum- 

 ference, have most of their cavities obliterated by internal thick- 

 enings. The phellogen-ring is also well marked, and 3-5 layers 

 of dead cells lie outside the cork. Cortex and pith show sacs 



