Danaea simplicifolia , Rudge . 1 1 7 
which emerges just beneath the cotyledon 1 . In plants of 
Danaea simplicifolia , in which several leaves had already 
expanded, there was no external evidence of adventitious 
roots. These, when they do appear, come out through the 
bases of the leaves next below those to which they belong, 
and for a long time, at any rate, there is only one root to 
each leaf. 
The ground tissue of the primary stem is composed of 
ordinary parenchyma being fairly bulky. Tannin-sacs 2 * of 
the ordinary Marattiaceous type early make their appearance, 
but the mucilage-canals do not do so till comparatively late, 
there being no sign of them in the first few leaves at any rate. 
The Root. 
The primary root has a simple diarch stele, the xylem- 
plate lying in approximately the same plane as the bundles 
of the first two leaves. The phloem occupies the usual 
position, and is of the kind characteristic of the group. 
Danaea agrees with Angiopteris 3 in having a diarch xylem- 
plate, but differs from Marattia Douglasii , which has usually 
a tetrarch stele 4 . There is a well-marked endodermis, and 
again in this respect Danaea simplicifolia agrees with Angio- 
pteris and differs from M. Douglasii 5 . 
The primary root emerges from the prothallus long before 
the cotyledon (cf. Fig. 8). The embryo of this figure was, it 
is true, the only one sufficiently advanced to show this ; but 
there is no reason to regard this as other than the normal 
case. Moreover, two of the embryos figured by Prof. Farmer 
show a tendency in the same direction 6 . This seems to 
completely nullify the importance attached to the converse 
condition, found in M. Douglasii , by Prof. Campbell 7 . 
It is rather interesting to note that the root-hairs of the 
primary root are of exactly the same type as the rhizoids of 
1 Farmer, loc. cit., p. 270. 2 Farmer, loc. cit., p. 269. 
3 Leclere du Sablon, loc. cit. 4 Campbell, loc. cit. (a), p. 14. 
5 Loc. cit. (a), p. 14. 6 Loc. cit., Figs. 9 and 10. 
7 Loc. cit., p. 14. 
