128 Bower.— Is Eusporangiate or Leptosporangiate 
infinitely more perfect than of the carboniferous plants, 
and that of the fossil Ferns here entered among the Poly- 
podiaceae, the details of the sporangia are not known in 
any one case. Bearing these points in mind, it appears 
that the Ophioglossaceae stand roughly in the present as in 
the past, that the Marattiaceae of the coal preponderated 
greatly over those of the present era, both in genera and 
species, while the Polypodiaceae, which are the most typical 
Ferns of the present time, are represented in the coal by 
relatively few forms which are only doubtfully referred to 
this family. Stur further states that the Gleicheniaceae, 
Osmundaceae, and Schizaeaceae were entirely absent from 
the coal, and suggests for them a post-carboniferous origin ; 
though I do not consider that, in the absence of all know- 
ledge of their vegetative organs, the sporangia above 
described demonstrate beyond doubt the presence of Os- 
mundaceous Ferns in the coal, I should not be prepared 
to maintain their absence in view of those facts. Speaking 
generally, the present Eusporangiate Ferns may be said to 
be the reduced remnants of a more prevalent race of 
former times, while the Leptosporangiates were in the 
main a race of later origin, and are now greatly more 
prevalent than in earlier periods. In the previous pages I 
have attempted to show that the comparison of the facts 
of structure and development of present living forms is not 
incompatible with the view that the Eusporangiates represent 
the more primitive type for the Filicineae : the palaeophy- 
tological evidence is clearly in favour of this, though it is 
not, and cannot be expected to be, absolutely conclusive. 
In the memoir already referred to at the opening of 
this paper 1 I have dwelt at some length upon the adaptive 
nature of the differences of bulk of the various parts of 
the sporophyte and gametophyte in the Ferns : having 
demonstrated that, as regards bulk of the young parts, the 
Ferns form a series, it was recognised that the more robust 
Eusporangiate forms are better suited in all their parts to 
1 Annals of Botany, vol. Ill, pp. 366-374. 
