218 SUMMARY OF CURKENT RESEAP.CHES RELATING TO 



Prothallus and Young Plant of Tmesipteris.— J. E. Holloway 

 {Trans. Proc. New Zealand Inst., 1918, 50, 1-44, 3 pis. and figs.). The 

 subject is treated in chapters, as follows : — Occurrence and habit ; 

 general form and structure of the prothallus ; the distribution of the 

 sexual organs ; development of the sexual organs ; the development of 

 the embryo ; development of the young plant ; development of the 

 vascular anatomy ; comparative remarks. The author compares his 

 results with those of A. A. Lawson, and finds himself in agreement in 

 many particulars — as to the subterranean saprophytic prothallus, its 

 brown colour and covering of i-hizoids ; its cylindric form, and its 

 branching ; its endophytic fungus ; the distribution of the antheridia 

 and archegonia scattered all over the surface; the structure of the 

 mature sexual organs ; the embryo borne on a prothallial protuberance ; 

 the peculiar lobular development of the epibasal portion of the embryo. 

 But he finds Lawson's prothalli to be much smaller and tender, with 

 twisted rhizoids, with a different distribution of the endophytic fungus, 

 and with the prothallium lobes pointed. The explanation may be that 

 under T. tannensis two species are included, Holloway's material being 

 of the form known as T. lanceolata, which differs from this type in both 

 habit and histological details. The author points out how^ the prothallus 

 of Tmesipteris differs from those of Ophioglossace^e and Lycopodiacese ; 

 and cites the evidence for the near affinity of Tmesipteris and Psilotum., 

 and for the connexion of these Psilotace^e with certain of the fossil 

 Sphenophyllales. He discusses the question as to whether the Psilotacese 

 are to be regarded as primitive, or as the result of reduction, or as being 

 recent adaptations ; he draws an analogy from the Equisetace^e and the 

 Lycopodiaceai, and gives a resume of what is known of Rhijnia Gwynne- 

 Vaughani, referred by Kidston and Lang. to a new class, Psilophy tales ; 

 and he concludes that the Psilotace^e are to be regarded as of a primi- 

 tive character. In a postscript he points out how^ his researches correspond 

 more closely with Lawson's second account of Tmesipteris than with the 

 first. A. G. 



Cantheliophorus, Bassler : New Records of Sigillariostrobus 

 (Mazocarpon).— M. Benson {Ann. of JBot., 1920, 34, 135-7). Some 

 criticisms of Bassler's recent paper on a Sporangiophoric Lepidophyte 

 from the Carboniferous — namely, Cantheliophorus. The view is put 

 forward that the material may be referred to Sigillariostrolus on the 

 ground of — (1) The general occurrence free from the axis of tlie cone; 

 (2) the form of the sporange and the bract ; (3) the occurrence of lateral 

 lines, some of which suggest the vascular pedicel and some the " lateral 

 lamella " of Mazocarpon ; (-l) the indication of a bulky sporange wall and 

 the relatively small spore-bearing region. Most of Bassler's specimens 

 are to be welcomed as further examples of Sigillarian microsporophylls, 

 of which previously only one incrustation record was known. A. G. 



Pit-closing Membrane in Ophioglossaceae. — Gertrude Wright 

 {Bot. Gaz., 1920, 69, 237-17, 2 pis. and figs.). An account of some 

 investigations of Helminthostachys zeylanica, Ophioglossum vulgatum and 

 Botrychium obliquwn, with a view to determining the presence or absence 



