Morphologie und Teratologie. 413 



glossum type; in Equisetum they are regarded as being directly seated 

 on the axis, and having originated there by a similar progression, they 

 would thus be non-foliar. It is pointed out that though a foliar theory 

 would be possible for Equisetum itself, it is not applicable to the 

 facts known for the fossil Calamarieae, which are so naturally related to 

 it. Thus the strobilus of the Equisetineae is of a rather different type 

 frotn that of the Lycopods, Psilotaceae, or even the Ophioglossaceae, in 

 all of which there 'is a constant relation of the spore-producing parts to 

 the leaves; in the Equisetineae no such constant relation exists; the 

 leaves and sporangiophores may be in juxtaposition, as in Calamostac/iys, 

 without exactly matching numerically; or the sporangiophores may occur 

 in larger numbers and in several ranks, between successive leaf-sheaths, 

 as in PJiyllotheca and Bornia ; or without any leaves at all, as in Equi- 

 setum. Thus, on a non-phyllome theory the latter may be held to be only 

 an extreme case of what is seen in certain fossils. 



The Ferns, notwithstanding their apparent divergence of character 

 from other Pteridophytes may also be regarded as strobiloid forms, with 

 greatly enlarged leaves; the primitive sori of the Simplices resemble the 

 sporangiophores of other Pteridophytes; the more complicated soral con- 

 ditions of the Gradatae and Mixtae were probably derivative from these, 

 the Chief difference being due to the interpolation of new sporangia, an 

 innovation which is in accordance with biological probability, as well as 

 with the palaeontological record. 



The efiect of the results thus obtained on the systematic 

 grouping of the Pteridophytes is then discussed; it is pointed 

 out that the Lycopods, Psilotaceae, Sphenophylleae, Ophio- 

 glossaceae, and filices illustrate lines of elaboration of a radial 

 strobiloid type, with increasing 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 distinction of Jeffrey does 

 not define phylogenetically distinct races, but is rather a re- 

 gister 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 neces- 

 sarily 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. u 

 The more recent investigations of Jeffrey, and of Lang, have 

 shown, however, that in the gametophyte of the Ophioglossa- 

 ceae, 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 Lyco- 

 podium; 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 Isoetes we Iearn that a combination 

 of cross characters is found in a megaphyllous 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 relat- 



