4 
Scott. — On the Fertile Shoots of 
a minute stele or mesarch bundle. In the later sections of the series 
another axillary shoot (in 2793) and two or three more branches or buds are 
met with. In two of these (in slide 2789) there is an appendage in addition 
to the bracts, like that shown in PI. I, Fig. 2. In one case it is possible that 
a second appendage is present in the same bud. 
The fertile shoot is associated, though not very closely in this case, with 
a number of seeds. In the series of fifteen sections twelve distinct specimens 
of Mitrospermum compressum , A. Arber, occur. They present all the 
characters of the species, and there is no doubt as to their identification (see 
p. 18). None of them, however, show any special relation to the fertile 
shoots, so the evidence is simply that of association, and such force as it has 
depends on the high number of the associated seeds. One of the Mitro- 
spermum seeds (shown in sections 2792-4) appears to be young, judging 
from the comparative thinness of the cell-walls of the sclerotesta, but though 
this seed is in the neighbourhood of the second axillary shoot there is 
no indication of any connexion. 
Some of the sections of the Mitrospermum are interesting in themselves ; 
in one (section 2781) the prothallus is preserved ; another (2787) shows four 
pollen-grains in the pollen-chamber, and a third (2791) passes through the 
chalaza. Though these details are irrelevant to our immediate question, it 
has been thought worth while to figure the two former (PI. II, Figs. 15, 16). 
It is fair to mention that other seeds, Physostoma elegans and Conostoma 
oblongum , occur in the series, but only a couple of specimens of the former 
and one of the latter. 
We have next to consider the specimen of a fertile shoot associated with 
a vegetative stem of M. multirame} The stem is of the ordinary type, 
about 2 cm. in diameter, with a pith varying from about 7 to 9 mm. in 
diameter in different parts of the specimen, and wood from 2 to 2*5 mm. in 
thickness. It is thus a rather small and young stem (PI. I, Fig. 4). 
All the distinctive characters of the species, especially the very gradual 
convergence of the twin-bundles of the leaf-trace at the margin of the pith, 
are shown, though the preservation is not specially good. The stem, 
particularly in its lower part, bears a number of axillary shoots, of which the 
characteristic steles are conspicuous (PI. I, Fig. 4); they have the usual 
tangentially elongated or flattened form, and their secondary wood is thicker 
on the inner than on the outer face. 
The fertile shoot lies quite close to the stem (PI. I, Fig. 4) ; it is not 
much flattened, though the outline is irregular and distorted. The transverse 
dimensions are roughly 2-9 x 2 mm. In the section in which the shoot first 
appears (2564) the main stele is badly preserved, but at one end (A) a small, 
round, pithless stele has been given off, and there are traces of a minute distal 
1 The vegetative stem runs through the series 2563 to 2574, from below upwards; slides 2984 
and 2985 appear to be of the same stem, as are also the longitudinal sections 2575-8. 
