140 



Prof. F. 0. Bower. 



[Dec. 5, 



sources a general support of the relationship has been traced, the 

 nearest point of comparison appearing to be between 0. Bergianum 

 and PhyllogJossum Drummondii ; it is contended that this is not a case 

 of mere mimicry, but of real relationship, though such relationship 

 probably dates from a remote and unknown ancestry. 



Such a relationship would involve the idea of septation of the 

 simpler type of Lycopodinous sporangium, to form the spike of 

 Ophioglossum, but it has been shown that septation of a very similar 

 nature has occurred in the anthers of certain Angiosperms, and that 

 the developmental details of Ophioglossum are compatible with such 

 a view. The conclusion of Celakovsky is, therefore, regarded as 

 probably true, viz., " that both the Lycopodiaceae and Ophioglossaceae 

 sprang from a common stock, which had the simple sporophylls of 

 the Lycopodiaceae. The Lycopods are probably, of living plants, the 

 nearest prototypes of the Ophioglossaceae." Thus, the view put for- 

 ward is not new nor original, but, being now based on a wider area 

 of fact, may take rank as a reasonably probable theory. 



A comparison of the Ophioglossacese among themselves shows that 

 probably the genus Ophioglossum forms a series of increasing com- 

 plexity, extending from such types as 0. Bergianum or lusitanicum 

 to such forms as 0. pendulum and palmatum. Comparison of a large 

 number of specimens of the latter species shows that the many- 

 spiked condition is led up to by specimens with one, two, or three 

 spikes, which are matched by abnormal specimens of 0. vulgatum. 

 The view is put forward, that the many-spiked condition occasion- 

 ally met with in other species has become the typical state in 0. 

 palmatum, and that it has been brought about by a chorisis or 

 interpolation similar to that of the stamens of certain Angiosperms. 

 It is further to be added that the insertion of the spikes is com- 

 monly on the adaxial surface of the frond, rarely upon the margin ; 

 the facts accordingly do not support the hypothesis that the many 

 spikes are of the nature of pinnae : thus, in Ophioglossum the pro- 

 gression appears to be towards multiplication of sporangia and 

 formation of a plurality of spikes. 



In Botrychium the progression appears to be from types such as 

 B. simplex, in which there is close similarity to a simple Ophio- 

 glossum, by branching of the spike which is closely connected with 

 enlargement and septation of the sporangia, to the condition seen 

 in such species as B. virginianum, the branching of the spike running 

 parallel with that of the subtending frond. The formation of 

 sporangia abnormally on the latter, a condition commonly seen in 

 B. Lunaria, but rare in most other species, is believed to be an 

 example of reversion of a part typically vegetative to the sporo- 

 genous condition, and not indicative of a common character of the 

 spike and the vegetative frond. Finally, Helminthostachys occupies 



