453 
Scott.—The Structure of Mesoxylon multirame . 
shoots, recognizable by their steles, which entirely agree with those of the 
type. But the particular interest of the specimen lies In the presence of 
a detached axillary shoot, clearly of the spe nature as the others, and 
itself branched. This shoot is intimately associated with seeds, apparently 
identical with Mitrospermum compression, A. Arber. 
Mr. Lomax has long been convinced that this seed belongs to a Meso¬ 
xylon , and I am inclined to agree with him, but at present the evidence is 
not conclusive, for no case of actual connexion between seed and shoot has 
yet been met with. The subject of the supposed fructifications, of which 
there are several specimens, must be postponed to another paper, for not all 
of them appear to belong to the species with which we are now concerned. 
One point, however, may be emphasized. It is now certain that the axillary 
shoots of M. multirame were branches of a special kind, quite different in 
their characters from the parent axis. The axillary shoot itself, character¬ 
ized by Its peculiar flattened stele and marked bilateral symmetry, appears 
to have been naked ; there Is no clear proof at present that it bore leaves. 
It branched, however, repeatedly ; its branches were distichously arranged, 
their insertions lying in the principal plane of the narrow stele. The branches 
bore numerous scale-leaves or bracts, and also other appendages, the nature 
of which will be discussed elsewhere. The highly specialized character of 
the axillary branch-systems renders it probable that they were connected 
with reproduction, and the close association with seeds suggests that they 
may have constituted the female inflorescences of the plant. 
There is evidence from a large specimen, probably belonging to this 
species, that the stem also branched in an ordinary vegetative manner, the 
branch in this case repeating the characters of the main axis. 
Summary. 
The summing up of the main characters of the species may take the 
form of an amended diagnosis : 
Mesoxylon multirame , Scott and Maslen, 1910. 
Leaf-bases moderately crowded, not quite covering the surface of the 
stem. 
Pith large, discoid, with a persistent outer zone. 
Twin bundles of the trace remaining distinct for several internodes after 
reaching the pith, and never definitely fusing before they become merged 
in the woody zone. Trace dividing into eight bundles in the cortex. 
Centripetal xylem persisting about as long as the two strands remain 
distinct. Sheath variable, limited to the region where the strands first reach 
the pith. 
Tracheides of the whole of the inner part of the wood spiral, reticulate, 
