1896-97- 1 THE GAMETOPHYTE OF BOTRYCHIUM VIRGINIANUM. 265 



THE GAMETOPHYTE OF BOTRYCHIUM VIRGINIANUM. 

 Bv Edward C. Jeffrey, B.A., 



Lecturer in Botany, University of Toronto* 



(Read 21st November, iSgy). 

 I. 



On account of their subterranean and inconspicuous prothallus and 

 the slow germination of their spores, the literature on the subject of the 

 sexual generation of the OphioglossacecB is somewhat scanty. 



Hofmeister' was the first to give an account of the gametophyte in 

 this group. His friend Irmisch sent him specimens of the ver}^ young 

 sporophyte o{ Botrychiiim Lunaria in 1854. On visiting the spot where 

 the young plants had been discovered, he found other examples, some 

 of which were still attached to the maternal prothallus. The latter, he 

 describes as being oval in shape and about a millimetre in length, of 

 light brown colour externally, and yellowish white in section. The 

 cells were filled with clumps of material not of a starchy nature. 

 AntJieridia were found mainly on the upper surface, the archegonia 

 being situated below. Root-hairs were sparingly interspersed among 

 the sexual organs. The antherozoids resembled those of the other 

 Filici)iei2, but were about one-half larger in size. The archegouia were 

 sunk almost level with the surface of the gametophyte. One prothallus 

 was found still attached to its spore, but attempts to germinate other 

 spores, under observation, were unsuccessful. No young embryos were 

 obtained, nor was it possible to study the development of the sexual 

 organs. As a result of the inferior position of the archegonia, the young 

 sporophyte appeared on the lower surface of the prothallus. The root 

 grew out first, indeed two roots often made their appearance, before the 

 first leaf became visible. The latter was bract-like and colourless. The 

 two following leaves resembled it, but they had, either one or both of 

 them, green tips. The fourth frond conformed to the usual type, and 

 probably made its appearance in the next period of vegetation. From 

 the situation of the embryo on the lower surface of the prothallus, the 



' Most of the material for this investigation w.ns secured by means of a g^rant from the Elizabeth 

 Thompson Scientific Fund. 



I. Abh.-ind, d k. Sachs. Gesellschaft d. Wissch. Bd. ii., pp. 657-662. 



