XXVili 
DESCRIPTION OF PLATE V.—continued. 
Fig. 7.—Portion of a transverse section of one of the bundles of vascular tissue — 
of Sigillaria elegans, x 20 linear. (From M. Brongniart.) See p. 131. 
The convex portion on the left, and which in the original stem is 
situated towards the centre, is composed of the medullary vascular © 
tissue formed of vessels irregularly disposed. 
The longitudinal bundles are the woody fibres arranged in a radiated 
circle: the smooth interspaces are medullary rays. q 
The two distinct roundish spots of vascular tissue on the right of the — 
ligneous zone occur irregularly on the outside of the woody circle 
and are supposed to be detached bundles of the ligneous zone ex- — 
tending towards the leaves. See p. 131. 
