368 Bower . — The comparative examination of the 
and the Marattiaceae and Ophioglossaceae, which approach the 
Cycadaceae at least in the characters of the sporophyte. The 
evidence adduced in this paper is to be taken as materially 
strengthening this view, while it is also intended as a contribu- 
tion to that knowledge which will be necessary for the final ar- 
rangement of the several sub-divisions of Ferns in sequence 
between these two extremes : thus the close relation of the 
meristems of the Osmundaceae, and especially of Todea 
barbara to the Marattiaceae, is clearly brought out. It is also 
seen that Amphicosmia (as an example of the Cyatheaceae), 
though so much larger than the ordinary Polypodiaceae, does 
not differ materially from them in the character of its meri- 
stems ; and again, judging from the evidence adduced, the 
relation of the Schizaeaceae appears to be closer to the true 
leptosporangiate Ferns than to the Osmundaceae, notwith- 
standing that on various grounds they may be regarded as 
more nearly connected with the Osmundaceae than are the 
Polypodiaceae or Cyatheaceae. 
As regards the sequence of the various groups of homo- 
sporous Ferns, various authors have arranged them in different 
ways — sometimes arbitrarily, sometimes with definite purpose. 
In the Synopsis Filicum 1 the order is : — 
I. Gleicheniaceae. 
II. Polypodiaceae [including Cyatheaceae and Hy- 
menophyllaceae] 
IIP Osmundaceae. 
IV. Schizaeaceae. 
V. Marattiaceae. 
VI. Ophioglossaceae. 
Russow 2 speaks of the leptosporangiate Ferns as constitut- 
ing six equivalent branches of the phylogenetic tree, and does 
not distinguish any one of them as specially approaching the 
Marattiaceae. Luerssen 3 gives the series thus : — 
1 Synopsis Filicum, Sir W. Hooker. 2 Vergl. Unters. 1872, pp. 194, etc. 
3 Handbuch d. syst. Botanik, 1879. 
