54 SUMMARY OF CURRENT RESEARCHES RELATING TO 



inches long and half an inch wide. Denuded axes are far more common 

 than those with cone-scales still attached, only three of which have 

 so far been recorded. One detached microsporange is described, and is- 

 shown to resemble certain incrustation specimens from the same horizon 

 described by Kidston, • A. G. 



Prothallia of Lycopodium in America. — Earle Augustus 

 Spessard {Bot Gazette, 1918, 65, 362). A correction of a previous- 

 statement by the author as to the prothallia of Lyco'podiam otscurum. 

 He now finds that they must be referred to L. conijjlanatum, and that 

 the real prothallia of L. oliscurum, which he has at last discovered, are 

 of the L. annotiaum type, and are to be described in detail in a later- 

 paper. A. G. 



Habitat and Mode of Occurrence in South Australia of two 

 Genera of Lycopods unrecorded for the State. — T. G. B. Osborn 

 {Trans. Roy. Soc. S. Australia, 1918, 42, 12 pp., 1 pi. and figs.). A 

 description of the association of plants in which Isoetes Drummondii and 

 Phylloglossum Drummondii are found to occur together. It is regarded 

 as a seasonal swamp developed upon alluvial soil within the formation 

 of sclerophyllous woodland. In South Australia both genera are members 

 of a considerable geophilous element within this association. However, 

 the claim of the author to be the first discoverer of Phylloglossum in 

 South Australia is anticipated by Dr. A. B. Rendle's record {Journal of 

 Botany, 1915, vol. 53, p. 25), the specimens being preserved in the 

 British Museum (Natural History). A. G. 



Gametophyte of Psilotum.— G. P. Darnell-Smith {Trans. Roy^ 

 Soc. Edinhurgh, 52, 1918, 79-91, 2 pis.). An account of the ecology,, 

 life-history, morphology and anatomy of the gametophyte of Ps//of?/w. 

 The spores require a special environment for germination. They produce 

 a cylindrical, radially symmetrical prothallus, which is a brown, subter- 

 ranean saprophytic tuberous body without chlorophyll, and contains an 

 endophytic fungus. Antheridia and archegonia are borne upon the 

 same prothallus. The antheridia produce spermatozoids having spirally 

 wound bodies and numerous cilia. The archegonia are very simple. 

 They consist of a venter containing the oosphere sunk in the prothallus^ 

 a ventral canal cell, and probably two canal cells, which latter are 

 bounded by .four tiers of four neck-cells that project at right angles to- 

 the surface. A. G. 



Gametophyte Generation of the Psilotaceae. — A. Anstruth£r. 

 Lawson {Trans. Roy. Soc. Edinhurgh, 52, 1918, 93-113, 5 pis.). An 

 account of the recently discovered gametophyte generation of Tmesipteris 

 and Psilotum.. This is a subterranean prothallus, light brown, cylin- 

 drical, branching, each branch having apical meristem. The prothallial 

 tissue is uniform, without differentiation into vegetative and reproduc- 

 tive regions. The prothallus is devoid of chlorophyll, is completely 

 saprophytic, and for its nutrition depends upon the co-operation of a 

 mycorrhizal fungus. This fungus is endophytic and not localized in its. 

 distribution in the body of the host, and may infect any cells except. 



