MATONINEAE 
569 
The process thus described may then be repeated in that central strand : 
it becomes cylindrical, forming the second vascular ring, which is. still 
connected at the nodes with the foliar 
system (Fig. 319 B), and a fresh central 
strand originates internally from it: 
this in its turn becomes cylindrical 
in the most advanced types, but still 
maintains its with the 
middle and outer rings in the neigh- 
bourhood of the nodes. The whole 
development is in fact an extreme 
type of the progression described by 
Gwynne-Vaughan in other solenostelic 
Ferns.!_ He showed how an internal 
vascular system may arise by progres- 
sive elaboration from a local thickening 
of the margin of the leafgap of the 
original solenostele. In AZa/onia this 
development is the same, but it may 
be twice repeated. 
connection 
It is indicated by the palaeophy- 
tological evidence that the 
Matonia-type is an ancient one it 1s 
not among the earliest. This accords 
with the soral and anatomical char- 
acters; for the sorus, though of the 
Gleicheniaceous type, and still form- 
ing its sporangia simultaneously as in 
other Simplices, shows an advanced 
feature in the indusium, as also in 
while 
the lateral dehiscence, and _ small 
spore-output. Anatomically the indi- 
cations are of the same _ nature: 
Matonia accords with G. pectinata in 
the solenostelic structure, but carries 
that line of elaboration much further. 
Finally, in the rhizomic habit and in 
FIG. 319. 
Matoxuia pectinata, drawings from wax models of 
the stelar system. A=froma young stem showing 
node. 4=from an older stem, showing node seen 
from behind. C=still older node, seen from in 
front. A X25. (After Tansley and 
Lulham.) 
CX 10. 
Bx 12. 
the branching of the leaf there appears to be further similarity: there is 
indeed sufficient reason to regard the Matonineae as a family related to 
the Gleicheniaceae, but advanced in several respects beyond that type, 
in directions which are represented more fully in other series of Ferns. 
1 Ann. of Bot., xvii., p. 703. 
