Observations on the Anatomy of 
Solenostelic Ferns. 
Part II. 
BY 
D. T. GWYNNE- VAUGHAN, M.A., 
Demonstrator in Botany at the University of Glasgow. 
With Plates XXXIII, XXXIV, and XXXV. 
HE terms used to indicate the different types of vascular 
JL arrangement in plants have recently become so numerous 
and varied that before going on to the descriptive part of this 
paper it is necessary to explain why some of those employed 
in it were chosen. So far as the Cyatheaceae and Poly- 
podiaceae are concerned it is no longer advisable to make use 
of Van Tieghem’s term ‘polystely’ for those cases in which 
the single central cylinder of the young plant becomes divided 
up into several separate portions, because it is now quite clear 
that none of the so-called * steles ’ that result can properly be 
regarded as equivalent to the original central stele. It has 
therefore been decided to adopt the term ‘ dictyostele/ 
recently proposed by Brebner 1 , for the tubular network of 
vascular tissue that arises by the occurrence and overlapping 
of gaps in a solenostele. The separate portions into which 
1 Brebner, On the anatomy of Danaea and other Marattiaceae, Annals of Botany, 
vol. xvi, no. lxiii, p. 523, 1902. 
[Annals of Botany, Vol. XVII. No. LXVIII. September, 1903.] 
