Plate III.('0- 

 Bougainvillea glabra. 



Fig. 1. Micro -photo-lithograpli of transverse section of stem, of 

 several years' growth, and about one-fifth of an inch in diameter; 

 magnified 33 diameters. The specimen was stained \vith aniline 

 dye, by which means the different tissues are more readily dis- 

 tinguished from each other. The outermost dark zone is the some- 

 what fissured corky layer. The pale zone just within it consists of 

 the younger cork-cells just emerging out of the phellogen, and not 

 yet tangentially flattened. The dark zone just within this is the 

 external coUenchymatous portion of the outer rind-parenchyma, 

 and the pale zone just within that is the non-collenchymatous 

 portion of the same. The dark line just within this indicates the 

 extra-fascicular bast-fibres; and within this again there is a pale 

 zone of considerable thickness, consisting externally of the secondary 

 rind-parenchyma, and internally of the extra-fascicular cambium 

 (compare with Plate Ill.(a), fig. 2). Then we come upon the zone 

 of secondary thickening, with small -celled matrix, in which are im- 

 bedded the secondary bundles. These bundles are disposed in 

 irregidarly radiating lines, separated from each other by lines of 

 matrix which simulate medullary rays, but with which, as remarked 

 by Petersen, they must not be confounded. In the centre of the 

 stem we have the primary bundles irregidarly scattered in a large 

 celled matrix. Across the duct marked x is stretched the reticu- 

 lated septum represented in Plate III.(^), fig. 3. 



Plate III.(//). 

 Boifr/ainviUen glahra. 

 Fig. 2. Transverse section of outer portion of stem <if same age 

 as the foregoing ; magnified 200 diameters. 

 ck. = Cork, 



j)h. = Younger cork-cells developing out of phellogen. 

 pijK — Primary rind-parenchyma outside the extra-fascicular 

 Hbriform fibres. The outer cells of this zone are 

 coUenchymatous, although not so markedly so as 

 in the younger stem. 

 efl. = Extra-fascicular libriform fibres. 



sri). = Secondary rind -parenchyma, internal to the last, and 

 developed o\it of the subcortical meristem (extra- 

 fascicular cambium). The larger cells in this 

 zone contained bundles of acicular crystals. 



