BY JOHN SHIRLEY AND C. A. LAMBERT. 603 



Milletia australis F.v.M., M. megasperma F.v.M., Se^iecio tamoides 

 DC, Solanum Wendlandii Hook, f., and 2'ecoiiia jasminoides 

 Lindl , etc., etc. 



(a.) CCELOSPERMUM PANICULATUM F.V.M. (Plate Ix., fig.l). — 



Although this stem is normal in having a single ring of cambium, 

 and in regard to the formation of secondary wood, the pith pre- 

 sents peculiarities. It is made up of two elements; one, the 

 ordinary pith-cell, containing starch: and the other, found mainly 

 in the centre of the pith, a thick-walled, sclerotic cell. The 

 latter form strands which do not extend to the circumference of 

 the pith. They are akin to the gum-resin sacs, described by 

 Karsten,* in the allied genera, Cinchona and Ladenbergia. 



(b.) Milletia australis F.v.M. (Plate Ix., fig.2). — Although 

 normal in the development of its cambium-ring, this stem shows 

 some special features. The pith is of very large cells, and, in 

 transverse section, these seem to be radially arranged, forming 

 conical masses. In the rays, the cells are elongated, and have 

 not the usual hexagonal outline. The cambium-ring is very 

 well defined, and, outside the bast, is a sclerenchymatous ring, 6 

 to 8 cells in depth, with intervals in which are inserted a few, 

 much larger, thinner- walled cells, evidently a transfusion-tissue. 

 Sacs containing single crystals abound in the cortex, and others 

 with much larger single crystals are scattered through the pith. 



Milletia megasperma F.v.M. — The arrangement of the pith 

 is normal. The wood- vessels form radial rows, with large masses 

 of murally arranged wood-fibres between them. There is a thick 

 sclerenchymatous ring outside the bast, with transfusion-tissue 

 at intervals; but, in this species, the thin-walled cells are oval, 

 and elongated along radii passing through the transfusion-tissue. 

 A second, much narrower, sclerenchymatous ring separates the 

 periderm from the cork. The medullary rays differ little, in a 

 transverse section from the wood-parenchyma. 



(c.) Solanum Wendlandii Hook, f., (Plate Ixi., fig. 3). —The 

 central pith is of large cells. The ring of wood is very regular, 

 the wood-fibres showing very even ranks, the cells increasing in 

 size towards their inner boundary, and gradually merging in 



'" Karsten, Die medic. Chiiia-rindeu Neu-Grenadas, Ges. Beitr., p. 382. 



