222 MR. W. ARCHER ON THE MINUTE STRUCTURE AND 
hard to obtain a reply; nor do I think that, without the opportunity to examine a 
Ballia-specimen kindly sent me by Professor Thiselton Dyer (also from Kerguelen’s 
Land, collected by the Rev. A. E. Eaton) (Pl. XXVIII. figs. 13-18), I should have been 
able to satisfy myself on this point from the specimen in Mr. Moseley's collection, 
owing to the extremely crowded and nearly impenetrably dense investing envelope. 
To try to follow out, then, the relation of the cortical cells to the rachises they invest, 
we must now revert to the ramification-cells of the second degree before described. 
These we left as so many five-sided cells—that is to say, after the formation of the 
septum cutting off therefrom the portion destined to become the first joint of the 
lower minor accessory branch. In certain of these yet another curved septum makes 
its appearance: this, as might be expected, from the later period of its formation, is, by 
comparison, thin ; and I have not been able to see in it the usual pit (or pair of pits) ; 
but I would not say that they may not be there (РІ. XXVIII. fig. 11, г). This 
septum reaches from a point about one third of the distance from below upwards of 
the septum cutting off the first cell of the accessory branch, to very near the lower 
angle of the cell (ramification-cell of the second degree). It is much curved, and has 
its convex side upwards or towards the cavity of the cell, and its concave side towards 
the portion cut off. 'The upper portion is, as will be seen, still five-sided, the new 
side (made by the new septum) being considerably arched. This portion seems never 
again to divide or grow in any way, thus as if of no further moment (ғ c^, fig. 18). The 
lower portion сиё off therefrom is at first subtriangular or subquadrangular, one side 
exposed—that is, external (being the lower outer one of the original ramification-cell of 
the second.degree, as previously described) ; the other a portion (scarcely one third) of 
the septum, cutting off the first joint of the accessory branch; and another the new 
curved septum—which latter, if it gradually passes as far as the lower angle, causes 
the new cell to be trilateral; if, however, it terminates (ere it reaches that) somewhere 
near the angle, and against the adjacent side of the ramification-cell of the first degree, 
then we have a cell of quadrilateral outline. "This last cell then, as will be seen, when 
it is produced, might possibly correctly be called a ramification-cell of the ¢hird degree 
(пе, fig. 18). 
The next stage seems now to be, that the outer lower margin of this ramification- 
cell of the “third degree” becomes, as it were, somewhat abruptly pushed or bulged 
out downwards at about its middle point—this bulge soon, however, taking a more 
outward and lateral direction, the thick membrane becoming somewhat doubled upon 
itself Sometimes one might fancifully suppose that this doubling outwards laterally 
got some assistance by a mechanical “dint” from without (т, fig. 17), imparted a little 
to one side of the nearly similar bulge from within ; for the outline now shows this twice 
bent appearance. This doubling upon itself, backwards and outwards, becomes more 
pronounced ; the lower portion becomes enlarged and inflated ; and soon there is presented 
a large ovate external addition to this ramification-cell of the third degree (cort. cell 1, 
figs. 17, 18). This accession, in length downwards (alongside of the rachis-cell below), P 
about equal to that of the older portion above when first formed, and in width twice 
as great as that of the original portion; at the same time this additional ovate external 
