470 MISS T. L. PRANKERD ON THE STRUCTURE OF 
There is occasionally some appearance of continuity between the contents 
of one fibre and another, and also between the contents of the fibres and 
the epidermal cells, but this is not so clear as in the case of the epidermis ; 
and in view of the doubt as to what does represent the original protoplast, 
if indeed that be represented at all, we cannot lay much stress on these 
appearances, 
The transverse section К. 22, already referred to several times, is quite 
unique in showing another feature of the fibres—i. e., their modification in the 
immediate vicinity of each vascular bundle. Here they become more delicate, 
and are generally almost filled with pale brown homogeneous contents ( P1. 22. 
fig. 2). Some differentiation of the cells exterior to a vascular bundle—e. g., 
the storage of starch—is often shown in recent plants ; and though it would 
seem impossible to arrive at the precise physiological significance of the 
appearance deseribed above in a fossil plant, we at least know that such is 
definitely indicated, for the occurrence of specialized cells seven or eight 
times in connection with an unmistakable vascular strand is too great for 
mere coincidence. 
(11.) The Soft "Tissue.—As before stated, thisis seldom well preserved, but 
since it is clearly shown in a few preparations, and indicated in many others 
from which it has mostly disappeared, we must conclude that it was a 
constant feature. 
It is greatest in extent in the canopy, where it formed the filling tissue of 
the chambers (РІ. 23. figs. 15 & 19), which in their greatest extent measure 
about half a millimetre radially in a transverse section. From the point 
where the cusps of the canopy lining cease to touch the outer shell the 
masses of filling tissue become tangentially confluent, and when the integu- 
ment unites with the nucellus the soft tissue continues as a layer a few cells 
broad, forming а lining to the shell, and perhaps represents the “ inner flesh ” 
of Cyeadean seeds. The specimen 1885 В (text-fig. 2, p.473) in the British 
Museum, and to a lesser extent В. 21 a, show that the slight angling which 
was mentioned (p. 462) as an external feature of the seed is visible also in 
the internal boundary of the shell, and, since the nucellar membrane is 
circular in section, the soft tissue is wider in extent just opposite each 
external angle. These columns of tissue may thus be regarded as slight 
downward continuations of the canopy chambers. At the base of the 
seed the soft tissue is again better developed, filling up the space between 
the fibrous layer, the nucellus, and the tracheal plate (cf. А, p. 464). The 
only section in which it can well be studied in this locality is R. 20 a (2), 
the plane of which, though oblique to the axis of the seed, cuts the shell 
almost at right angles, owing to its curvature near the chalaza (ef. plotting 
on А, р. 464). The tissue here has the appearance of parenchyma, the cells of 
