406 



Mr. W. H. Lang. On the Prothalli of 



prothallus of OpMoglossum pedunculosum* was described by Mettenius in 

 1856. It was subterranean, consisting of a small tuber, from which an 

 erect cylindrical body proceeded. On the latter, which in some 

 instances was observed to reach the surface and turn green, the sexual 

 organs were borne. The first divisions in the germinating spore of 

 0. pendulum! are described and figured by Campbell. The prothalli 

 of two species of BotrycMum are known, both of which are subterranean. 

 That of B. virginianum % is thick r and flattened, and in its structure and 

 in the localisation of the sexual organs on the upper surface clearly 

 dorsiventral. The prothalli of B. Lunaria,§ however, have sexual 

 organs on all sides. In the Lycopodiacece the prothallus is well known 

 in the heterosporous forms and in Lycopodium. The sexual generation 

 is entirely unknown in the Psilotacece and in Phylhglossum. If the 

 author is correct in attributing the prothallus to be described below to 

 Psilotum, the only two isolated genera of existing Vascular Cryptogams 

 in which the gametophyte is entirely unknown are Tmesipteris and 

 Phylloglossum. 



Fig. 1. Fig. 2. Fig. 3. 



Fig. 1. OpMoglossum pendulum, old prothallus from above. ( x 7.) 

 Fig. 2. Eelmintliostacfiys zeylanica, prothallus, bearing antheridia, from the 

 side. ( x 7.) 



Fig. 3. Psilotum, sp., prothallus from the side and slightly from above. ( x 7.) 



OpMoglossum pendulum. 

 The sporophyte of this plant was, for the most part, found growing 

 on the humus collected by such epiphytic ferns as Polypodium querci- 

 folium and Asplenium nidus. A large mass of the former, with the 

 OpMoglossum growing upon it, was collected in the Barrawa Forest 



* 1 Filices Horti Bot. Lipsiensis,' Leipzig, 1856, p. 119. 



f ' Mosses and Ferns,' London, 1895, p. 224. 



% Jeffrey, 'Trans. Canadian Institute,' 1896-7, p. 265. 



§ Hofmeister, ' Higher Cryptogamia,' London, 1862, p. 307. 



