Notes. 623 
of new sporangia, an innovation which is in accordance with biological 
probability, as well as with the palaeontological record. 
The effect of the results thus obtained on the systematic grouping 
of the Pteridophytes is then discussed; it is pointed out that the 
Lycopods, Psilotaceae, Sphenophylleae, Ophioglossaceae, and Filices 
illustrate lines of elaboration of a radial strobiloid type, with increas- 
ing size of the leaf. The division of Pteridophyta by Jeffrey, on 
anatomical characters, into small-leaved Lycopsida and large-leaved 
Pteropsida is quoted ; but it is concluded that the anatomical distinc- 
tion of Jeffrey does not define phylogenetically distinct races, but is 
rather a register of such leaf-development as differentiated them from 
some common source. It is contended that the Ophioglossaceae and 
Filices, which constitute Jeffrey’s Pteropsida, are not necessarily akin 
on the ground of their large leaves, and consequent phyllosiphonic 
structure ; but that they probably acquired the megaphyllous character 
along distinct lines. The opinion of Celakovsky is still held, ‘that 
the Lycopods are probably of living plants, the nearest prototypes of 
the Ophioglossaceae/ The more recent investigations of Jeffrey and 
of Lang have shown, however, that in the gametophyte of the Ophio- 
glossaceae there is an assemblage of ‘ Filicinean ' characters, which 
differ from those of Lycopodium itself. But Celakovsky’s comparison 
is with the Lycopods , not with the genus Lycopodium ; so far as the facts 
go, increasing ‘ Filicinean ’ characters of the gametophyte follow in 
rough proportion to the larger size of the leaf; thus from Lsoetes we 
learn that a combination of cross-characters is found in a mega- 
phyllous Lycopod type. What we find in the Ophioglossaceae is that 
in conjunction with their more pronounced megaphyllous form, still 
retaining, however, the Lycopodinous type of the sporophyte, they 
show more pronounced ‘ Filicinean ’ characters of the gametophyte 
and of the sexual organs. It is unfortunate that the facts relating to 
the gametophyte of the Psilotaceae and Sphenophylleae are not avail- 
able in this comparison. 
What the meaning is of this parallelism between leaf-size and 
characters of the sexual organs it is. difficult to see ; a further difficulty 
in its interpretation lies in the fact that for the Equiseta the parallel- 
ism does not hold ; there ‘ Filicinean ’ characters of the gametophyte 
accompany entirely non-Filicinean characters of the sporophyte, the 
latter showing nearer analogy to the Lycopods than to the Ferns. 
Such cross-characters are difficult to harmonize with any phylogenetic 
