Notes . 777 
solenostele, causing it to project somewhat towards the centre of the 
stem. 
A similar marginal enlargement also occurs in D. adiantoides ; and 
here it is continued past the leaf-gap, forming a ridge on the internal 
surface of the solenostele, running from one leaf-gap margin to 
another. In the internode this projecting portion of the xylem 
becomes separated off from the rest and surrounded by a phloem 
of its own; however, it remains always included within the same 
endodermis. 
In Dicksonia rubiginosa the typical vascular ring is interrupted by 
gaps other than those due to the leaf-traces, and it may therefore be 
termed polystelic. In addition there are two or three small accessory 
steles lying within the vascular ring. Throughout the internode the 
course of these internal steles is quite free from the vascular ring, but 
at each node one of them approaches the free margin of the leaf-gap, 
and completely fuses with it, separating off again after the leaf-gap has 
become filled up. 
Pteris elata , var. Karsleniana , has a typically solenostelic vascular 
ring, and also possesses internal accessory steles, which behave in 
a manner quite similar to those of Dicksonia rubiginosa ; but they 
are relatively larger, and frequently they all fuse up together so as to 
form a second, inner, completely closed vascular ring. 
It is suggested that the several internal steles and vascular rings 
that occur in the Saccolomas and in Matonia pedinata are also of the 
same origin and nature as those described above. 
The relation of the internal accessory steles in certain Cyatheas 
to those of the above-mentioned Ferns is also discussed. 
D. T. GWYNNE-VAUGHAN. 
Glasgow. 
ON THE ANATOMY OP DANAEA AND OTHER MARAT- 
TIACEAE 1 . — Various species of the Marattiaceae were studied for the 
comparative anatomy of the adult structure, and Danaea simplicifolia , 
Rudge, for the development of the vascular system. 
i. Development of the vascular system of Danaea simplicifolia. 
The primary vascular axis is a simple concentric stele. The xylem 
1 Abstract of paper read before the Botanical Section of the British Association, 
Glasgow, September, 1901. 
