368 West. — A Contribution to the Study of the Marattiaceae. 
sporophyte of Danaea , the stelar system is not complicated so early by 
the influence of the adventitious roots as in the case of Angiopteris , in which 
the first adventitious root is given off nearly opposite the first leaf (cf. 
Farmer and Hill, 29, PL XVI, Fig. i, with Text-fig. 3, A, of the present paper). 
In a similar way the simple traces of the fifth and sixth leaves (Text-fig. 
4, A, l.t. 5 and l.t. 6 ) traced downwards appear to approach one another 
and ultimately enter into close association, giving rise to a single strand, 
which is more or less crescent-shaped in section. This strand at a still 
lower level becomes united with the fused traces of leaves 3 and 4. 
The trace of the third root joins the stem-stele close to the point of fusion 
of the traces of the fifth and sixth leaves. 
'■>.1.3. 
Text-fig. 5. Danaea alata, Sm. Front view of the model represented in Text-fig. 4, A. 
c.s., commissural strand ; l.t., leaf-trace ; r.t., root-trace. 
Up to this point, the description of the earlier stages in the development 
of the vascular system in the genus Danaea as given by Campbell (20, 
p. 174) so closely agrees with the arrangement of the bundles as I have 
found them in the species studied by me, that I cannot do better than quote 
his summary word for word : 
{ The vascular system in the young sporophyte of Danaea begins as 
a single axial strand, which is continuous through the cotyledon and root. 
At a very early period a second vascular bundle or stele is formed in the 
second leaf connecting with the primary strand, and this is followed by a 
similar single strand or stele in each succeeding leaf, up to about the 
seventh. Up to this time, except for the steles of the secondary roots, the 
whole vascular system is built up of united leaf-traces and there is no cauline 
bundle in the strict sense of the word, although we may speak of the bundle, 
or stele of the stem, as soon as there is a solid central strand formed b'elow 
