THE FERNS 137 
, 
attracts the attention of the botanist. The Leptosporan- 
giates, on the other hand, occur everywhere in the most 
astonishing profusion and variety, often constituting 
the most conspicuous feature of the flora of certain 
districts, especially in the higher mountains. 
The conclusion is irresistible that in the Leptospo- 
rangiate we have to do with a comparatively modern 
type of plants, eminently adapted to existing conditions 
and competing successfully with the highly specialized 
flowering plants. The small number, both of species 
and individuals, among the Eusporangiates points to the 
opposite condition in their case. They show every evi- 
dence of plants that are being worsted in the struggle 
for existence by their more specialized competitors. 
A study of the anatomy of the sporophyte as well as 
the gametophyte confirms this view. We find that the 
gametophyte in the Eusporangiates approaches that of 
the liverworts much more closely both in its structure 
and long duration, and the reproductive organs are 
much more like the liverwort type than are those of 
the leptosporangiate ferns. The embryo also remains 
much longer connected with the gametophyte, and the 
differentiation of its members does not take place until 
a later period. Finally, the sporophyte has simpler 
tissues, and the sporangium is of a less specialized 
type, approximating the conditions found in the highest 
liverworts. In short, the theory of the Eusporangiate 
being primitive and presumably an older type than the 
Leptosporangiate is borne out by every detail of their 
structure. 
That the Leptosporangiates have been derived from 
the Eusporangiates is indicated by the number of 
