320 SUMMARY OF CURRENT RESEARCHES RELATING TO 



illustrate£lines of elaboration of a radial strobiloid type with increasing 

 size of leaf. 



The author holds Celakovsky's opinion that the Lycopods are pro- 

 bably the nearest living prototypes of the Ophioglossaceas. The latter 

 in conjunction with their more pronounced megaphyllous form still 

 retaining the lycopodinous type of the sporophyte, show more pro- 

 nounced filicinean characters of the gametophyte and of the sexual organs. 

 The meaning of this parallelism between leaf -size and characters of the 

 sexual organs is not obvious ; in the Equiseta it does not hold ; these 

 filicinean characters of the gametophyte accompany entirely non- fili- 

 cinean characters of the sporophyte, the latter showing nearer analogy 

 to the Lycopods. Such cross characters are difficult to harmonise with 

 any phylogenetic theory ; hence the Equisetineae are placed in an iso- 

 lated position. 



Thejfollowing grouping is suggested : — 



Pteridophyta. 



I. Lycopodiales. 



(a) Eligulatm — Lycopodiaceas. 



(b) Ligulatce — Selaginellaceas, Lepidodendraceas, Sigillaria- 



ceaa, Isoetaceae. 

 II. Sphenophyllales. 



Psilotaceas, Sphenophyllaceaa. 



III. Ophioglossales. 



Ophioglossaceae. 



IV. Filicales. 



(«) Simplices — Marattiaceas, Osmundacea3, Schizasacese, 



Gleicheniaceag, Matonineas. 

 (V) Qradatm — Loxsomaceaa, Hymenophyllaceae, Cyatheaceae, 



Dicksoniea?, Dennstasdtiinae, Hydropterideas (?) 

 (f) Jlixtce — Davallieae, Lindsayeaa, Pterideas, and other 

 Polypodiacea3. 

 Y. Equisetales. 



Equisetaceae, Calamarieae. 



The actual connection of these series by descent must remain an open 

 question ; it is possible that some or all of them may have originated along 

 distinct lines from a general primitive group, which may be provisionally 

 designated the Protopteridophyta. These were probably small-leaved 

 strobiloid forms, with radial type of construction, and with the 

 sporangia disposed on some simple plan. 



Botrychium.* — L. M. Underwood publishes an annotated index of 

 the known species of Botrychium containing 35 valid species and a 

 variety ; and of these there are 6 that are described as new species, and 

 a seventh that is raised from varietal to specific rank. The synonymy 

 and distribution of each species are given. 



Spore-cavity Nucleus in Prothallia of Marsilia.j — W. C. Coker 

 has studied the behaviour in M. Drummondii of the nucleus left with 



* Bull. Torre/ Bot. Club, xxx. (1903) pp. 42-55 (1 pi.). 

 f Bot. Gaz., xxxv. (1903) pp. 137-8 (figs, in text). 



