388 Bower . — The comparative examination of the 
suggested by Vines. But, on the other hand, it may be argued 
that such evidence would be equally strongly in favour of 
a Lycopodinous affinity; and I anticipate that a knowledge 
even of minutest details of the meristems will not suffice to 
decide this interesting question. A final conclusion will 
have to be based on the broadest possible comparative 
grounds. 
POSTSCRIPT. 
Since the above was in type, the comprehensive work by MM. 
Van Tieghem and Doulist has come to my hands, in which 
the authors state (footnote, page 379) that there is only one 
initial cell at the apex of the root in Todea ‘ as in other ferns. 5 
It will be no surprise to me to find that in certain cases Todea 
barbare has a structure at the apex of the root more closely 
resembling that of the typical ferns than that which I have 
described. It will be noticed that I lay down no type of 
structure in Todea and Osmunda , but point out rather that 
‘ there is no such strict uniformity in these plants as is found 
in the roots of typically leptosporangiate ferns (above, p. 284) ; 
thus the reference of the whole meristem of Todea in certain 
cases to a single initial cell does not affect the general argu- 
ment, so long as it is recognised that a system of construction 
occurs not infrequently in these plants, such as I have 
described and figured, which is more complex than that which 
is so regular and prevalent in the Leptosporangiate Ferns. 
