. 224 MR. W. ARCHER ON THE MINUTE STRUCTURE AND 
apposed to one another and to the cells of the stem or rachis, leaving (especially lower 
down) very few “ intercellular spaces " (that is, intermediate bare places of the stem). 
When these occur they are of irregularly acutely lanceolate outline. Тһе largest inter- 
cellular зрасез are those, of course, through which the lateral branches or subsidiary 
rachises project—left necessarily by this descendent investing cortical stratum of cells as 
they pass downwards to each recurrent node or joint of the great stem or rachis, and 
from each of which in the same way new ones are given off in their turn. 
If a lateral rachis possesses such a cortical stratum of cells, they belong to and emanate 
from its own nodes; for such dependent cells on arriving at a branch never become 
directed upwards to cover it, but the system passes downwards by the same stem to 
the base. The cells forming this cortical stratum soon begin to give off their own 
branches (as described), and more and more copiously as they descend, until the great 
confused tangled ** plexus " is produced. 
. In order to complete the description of Mr. Moseley's plant we must now briefly revert 
to the ramification. We left the basal joint of a principal branch just formed by the 
cutting-off of the same from the ramification-cell of the first degree; and, in the same 
way, we left the first joint of a minor or aecessory branch just formed by the cutting-off 
of the same from the ramification-cell of the second. degree; but not all, indeed com- 
paratively only a few, of the ramification-cells proceed to this latter development. The 
greater number of the ramification-cells remain as of the * first degree "—that is, Вуе- 
sided; and the cell cut off gives rise, by continuous apical elongation and repeated . 
division, to a more or less long (sometimes very long), often very stout, filament. There 
is in such cases no septum producing a ramification-cell of the second degree formed ; and 
therefore no basal or accessory branch originates (Pl. XXVIII. fig. 3, its upper part). 
Each branch so emanating from a principal stem has (it need hardly be said) nearly 
always a similar one opposite thereto, arising, as described, from its own ramification- 
cell; and from every node for long distances such a pair of branches may be thus 
distichously given off. But it sometimes happens that a branch may be without an 
opposite corresponding one: the lateral margin of the side so deficient remains straight 
from bottom to top ; no ramification-cell is cut off—no branch (parts of fig. 2). 
And just in the same way in Mr. Moseley's plant these lateral branches (pinne) may 
be, and often are, quite simple for the whole of their length (that is, with linear sides), no 
ramification-cells being cut off, therefore no pinnules formed. 
But the overlapping of the laterally subdivided bases of the cells towards both fronts 
of the frond is more or less carried out in the joints of the lateral branches. The base of 
the first cell of a branch arising as described, and of each succeeding one, is, like that of 
the rachis-cells, laterally notched, but comparatively not at all so deeply: thus, like 
them, each cell sits astride the upper portion of the cell below; that of the first cell so 
bestrides, of course, the adjacent side of the ramification-cell. Тһе basal subdivisions of 
the cells of the branches which partially overlap the cells below, one on one front, the 
other on the other front of the frond, however, are not so prolonged and so conically 
tapered off downwards as are the cells of the principal stems or rachises, but are rounded 
off subsemicircularly, or with a merely convex outline. Still those nearer the base of 
