124 



THE FERN BULLETIN 



Davallia, Dicksonia, Aspidium, Gleichcnia, Goniop- 

 teris, Gymno gramma, HymenophylPum, Lygodium, 

 Onoclea, Osmnnda,. Phegopteris, Polypodium, Wood- 

 wardia and Ptcris. Among the fern allies we note 

 Equisetum, Isoetes,. Lycopodium, Salvinia, Ophioglos- 

 sum, Selaginella, and Tmcsipteris. Among the species 

 thought to be identical with living ones may be men- 

 tioned Nephr odium argutum, N. Goldicanum and 

 Onoclea sensibilis and six species of Equisetum namely 

 wrvense, laevigatum, limosum, robustum, scirpoides 

 and sylvaticum. The occurrence of these species in the 

 fossil condition makes the link connecting modern and 

 fossil ferns seem much more real than ordinary and 

 opens up a new view upon the continuation of the spe- 

 cies. Apparently some of these forms, inflexible as 

 they may appear, have nevertheless, been sufficiently 

 flexible to adapt themselves to the many vicissitudes 

 the race has encountered during the ages that have 

 elapsed since their appearance upon the earth and 

 enabled them to survive while multitudes of other 

 species that started with them have gone down to ob- 

 livion and left no sign. In this connection it is well 

 to remember, too, that many of the forms, once re- 

 garded as fossil ferns have been lately proved to be 

 not ferns at all but fern-like seed plants. 



INDEX TO RECENT LITERATURE. 



Readers are requested to call our attention to any 



errors in or omission from this list. 



Atkinson, G. F. The Relation betzi'cen the Sterile 

 and Fertile Leaves of Dimorphic Ferns. Fern Bulle- 

 tin Jl. 1911. — Reprinted from Linnaean Fern Bulle- 

 tin Vol. IV. 



Bates, J. A. The Fragrant Shield Fern. Fern Bulle- 

 tin Jl. 1911. — Reprinted from Linnaean Fern Bulle- 

 tin Vol. IV. 



