662 Campbell. — The Structure and Affinities of 
sporophytes of Macroglossum and Angiopteris. In both of these, however, 
tannin sacs are present in the cotyledon and in the later leaves, as well as 
in the stem and roots. The solid stele formed by the fusion of the early 
leaf-traces is retained longer in Macroglossum than in Danaea , and in this 
respect it also shows unmistakable likeness to Angiopteris. 
The Adult Sporophyte. 
The stem of the adult plant is a nearly globular caudex, a foot or more 
in diameter, completely covered by the closely set leaves. It appears to be 
strictly radial in structure. 
The leaves are more numerous than in Angiopteris , and the habit of the 
plant more compact. About a dozen leaves are present in the full-grown 
individual. 
The leaves have a relatively short stipe and the numerous pinnae 
closely set, giving the leaf much the aspect of a large Zamia . The leaflets 
are almost 50 cm. in length, with a maximum width of about 7 cm. The 
margin is quite entire, and the apex is sharply acuminate. The closely set 
veins usually branch close to the midrib, and each branch forks again, each 
vein in the fertile leaves having above its extremity the very much elongated 
sorus. The sori are closely set, and form a broad solid band separated from 
the margin of the leaflet by a narrow border. The sporangia are so crowded 
as to be scarcely distinguishable, and the appearance of the elongated sorus 
is very much like the synangium of Danaea, this resemblance being increased 
by the fact that the sorus is sunk in a sort of trough, and only the upper 
part of the sporangia appears above the surface of the leaf. Along each 
side of the sorus is a fringe of fine hairs, the indusium, which is much better 
developed than it is in Angiopteris. The leaf-base is much enlarged and 
the stipules extremely conspicuous (PI. XLVIII, Fig. c). The stipules are 
connected by a large commissure in front. 
PI. XLVIII, Fig. B shows the base of a small plant which, except for 
its size, is much like the fully grown one. The numerous stout roots 
are extensively branched, more so than is the case in Angiopteris. 
PI. XLVII, Fig. 4 6 shows a section of the petiole of a leaf from this 
plant. There were eighteen vascular bundles arranged in a circle inside 
the margin, and four bundles towards the centre of the section, one of the 
latter being much larger than the others. Three mucilage ducts (ml) were 
present. Separated from the epidermis by three or four layers of parenchyma 
cells, there is a broad band of sclerenchyma. 
Sections of the base of the stem of this same plant (PL XLVII, Fig. 45) 
showed a structure very much like that of the younger sporophyte. In the 
centre was a single large bundle, somewhat crescentic in section, and four 
bundles of smaller size, arranged in pairs, and probably representing double 
