88 MR. CHURCH ON THE FORM OF THE 
the cortical layer, and the interior parenchymatous tract in which 
the vascular bundle lies. This bundle has the form of a crescent, 
each end of the crescent being a volute. On the convex side of 
the crescentic fasciculus, and away from the axis of the stem, a few 
small dark tracts may be observed, and occasionally two or three 
others may be detected on those aspects of the volutes which most 
nearly approach. [Dr. Ogilvie finds the dark tracts on the con- 
cave aspect of the fasciculus: I have never observed this.] These 
dark tissues are hardly to be distinguished from true woody fibre. 
Figs. 6 b, 6c, 6d, 6e, 6f, 6g are diagrams intended to trace the 
origin of the vascular bundle which branches off to the first pinna. 
Not only do the various foreign forms of this plant exhibit the 
same disposition of the vascular tissue in the stipes, but an iden- 
tical arrangement in species of Osmunda generally thought to be 
distinct, such as O. Claytoniana. 
Fig. 6. 
b x5 e x 5. d, x 5. 
z * * 
€, X 5 Í, x 5 J, x 5 
Todea, the other genus of Osmundacee, ought to show some ana- 
logy in the form of its vascular bundles with that of Osmunda. A 
transverse section of a young frond of T. Africana 
(fig. 7) disclosed a row of scalariform vessels ar- 
ranged as a crescent, closely resembling that of 
A Osmunda regalis, but simpler. As in O. regalis, 
^S the fascicle had no dark sheath, but a few black 
fusiform woody fibres interspersed sparingly m 
the simple parenchyma of the base of the stipes: a white, soft and 
