68 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Use of Collodion Casts of Fossil Ferns.*- — A. G. Nathorst de- 

 scribes a method of making collodion impressions of the surface of 

 fossil plants for examination under the Microscope. He illustrates his 

 article with photographs of such casts, showing the structure of the 

 sporangia of fossil ferns, the epidermis of fern-fronds, etc. 



Prothallium of Lycopodium complanatum.f — -H. Bruchmann gives 

 a detailed account of the prothallium of Lycopodium complanatum, 

 illustrated by 47 figures. He describes the structure of the prothalliuin, 

 its occasional multiplication by means of vegetative offshoots, the sexual 

 organs, and the development of the embryo. 



Prothallium of Kaulfussia and Gleichenia.J — D. H. Campbell, 

 during his recent visit to Java, obtained material the study of which 

 has enabled him to give a detailed account of the prothallia, reproductive 

 organs, and embryo of Kaulfussia and Gleichenia. The prothallium of 

 Kaulfussia is large, and always contains an endophytic fungus. The 

 antheridia and archegonia are large, and are borne on the ventral 

 surface. All the organs of the embryo except the foot are of epibasal 

 origin. The shoot pierces through the prothallium and emerges on the 

 dorsal side. 



The prothallium of Gleichenia is of the "massive-midrib" type, 

 lobed, and containing an endophytic fungus. The antheridia are 

 restricted to the ventral surface, except in G. laevigata. They are in 

 the Javan species larger and more complex than described by Rauwenhof . 

 The archegonia are borne chiefly on the sides of the "midrib," and 

 are long-necked. The embryo apparently resembles that of the Poly- 

 podiacese. In sporelings the characteristic protostelic condition was 

 observed. 



Effect of Different Light-rays on Prothallia. § — A. Burgerstein 

 describes the effect of light-rays of different refrangibility upon the 

 formation of fern-prothallia. He gives a resume of the determinations 

 of previous authors, and states that as the result of his own experiments 

 he finds that under the influence of the blue rays the prothallia 

 generally form themselves in from a few days to weeks later (never 

 earlier) than under the influence of rays of lower refrangibility ; and he 

 appends a table of differences. 



British Ferns. || — E. Step has prepared a pocket guide to the British 

 ferns and fern-allies — an addition to his series of Nature handbooks. 

 After a general introduction, the species are treated separately. Each 

 species is represented by coloured figures, and several photographs 

 showing the plants in their natural habitats are reproduced. A classified 

 index to the families, genera, and species is added. 



Pteridophyta of the French Mediterranean Basin. IT — W. Herter 

 gives an account of the Pteridophyta of the French basin of the 



* Arkiv Bot., vii. No. 4 (1908). v 



t Bot. Zeit., lxvi. (1908) pp. 169-81 fags.). 



% Ann. Jard. Bot. Buitenzorg, ii. (1908) pp. 69-102 (8 pis.). See also Bot. Gaz., 

 xlvi. (1908) pp. 313-14. 



§ Ber. Deutsch. Bot. Gesell., sxvia. (1908) pp. 449 51. 



Wayside and Woodland Ferns. F. Warne and Co., 1908. 143 pis. 

 f Bull. Herb. Boiss., viii. (1908) pp. 794-820. 



