Anatomy of Solenostelic Ferns . 705 
external one, because the former are not only different in 
origin, but also later in development. In this it differs 
essentially from the suggestion put forward by Seward 1 and 
Boodle 2 , according to which it would appear that the internal 
vascular cylinder was split off as a whole from the original 
solenostele. It is to be regretted that young plants of none of 
these Ferns were available for examination, for no doubt they 
would provide much valuable information upon this question. 
The Cyatheaceae. 
The first observations upon the anatomy of this order were 
made about a hundred years ago by Plumier, who describes 
the appearance of the cut end of a stem of a Cyathea . The 
history of the subsequent attempts to arrive at a more 
satisfactory knowledge of their structure is unusually inte- 
resting, in that it discloses how the successive results were 
damaged and impeded by the interference of preconceived 
ideas based upon currently accepted theories. For instance, 
it is evident that the opinions held by most of the earlier 
anatomists upon the nature of the Fern stem in general were 
really the outcome of a statement made by Cesalpino so long 
ago as 1583 3 . Having first come to the conclusion that 
Ferns do not possess true seeds, Cesalpino proceeded to 
deduce the fact that they cannot possess true stems either. 
Hence, in the earlier part of the last century, we find that 
Brisseau-Mirbel 4 , Link 5 and Hanstein 6 all firmly refuse to 
recognize a true stem in the Ferns, insisting that their caudex 
is merely a sympodium of leaf-bases. Indeed, the authority 
of Cesalpino does not seem to have lost all its influence even 
1 The structure and affinities of Matonia pectinata, Phil. Trans. Roy. Soc. 
Lond., Series B, vol. cxci, p. 180, 1899. 
2 On the anatomy of the Gleicheniaceae, 1. c., p. 739. 
3 De plantis, lib. I, cap. 14. 
4 Elemens de botanique, vol. i, p. 122, 1815. 
5 Einige Bemerkungen fiber den inneren Bau der holzigen Farnkrauter, Linnaea, 
p. 414, 1826 ; also, Uber den Bau der Farnkrauter, Abhandl. d. K. Acad. d. 
Wissensch. z. Berlin, p. 375, 1834, an <l 1835, p. 82. 
6 Plantarum vascularium folia, caulis, &c., Linnaea, p. 65, 1848. 
