1896-97] THE GAMETOPHYTE OF BOTRYCHIUM VIRGINIANL'M. 267 



junction of the cotyledon and root, probably the foot, fastened the 

 young sporophyte to the base of the archegoniuin. The apical bud 

 appeared sometimes at the point of union of root and leaf, and some- 

 times further down on the root, thus simulating the adventitious buds 

 arising from the roots of the adult plant. 



The most recent contributions to our knowledge of this group is due 

 to the discovery of the gametophyte of Botrychiiivi virginianiini by 

 Professor Douglas Campbell'^ at Grosse Isle, Michigan, in 1893. The 

 prothallia were unfortunately, like those of Hofmeister's Botrychiuvi 

 Lunana, which they resembled in appearance, although larger in size> 

 too old for the study of the development of the sexual organs and 

 embryo. They are described as being flattened tubers with folded 

 upper margins, covered with root-hairs and bearing the reproductive 

 organs on the superior surface. Brown externally, white in section, the 

 lower part of the gametophyte harboured an endophytic fungus. The 

 archegonia had rather long and straight necks, while the anthei'idia were 

 quite endogenous like those of Equisetum and Marattia. No young 

 embryos were found, but only advanced young sporophytes, bearing 

 already the first or a subsequent leaf 



Professor Campbell was the first to bring about the germination of 

 the spores in this group. The process is exceedingly slow, requiring, 

 even in the warm climate of California, for Botrychiuni virginianum, 

 eighteen months or more, and for Ophioglossunt pendulum, somewhat 

 less than that time. The most advanced stages yet obtained by him, 

 had only undergone two or three divisions. Chlorophyll was found in 

 the young prothallium of Botrychiuni virgimamini, and a suspicion of 

 chlorophyll in that of Ophioglossum pendulum. This may have been 

 due merely to the fact that germination took place in the light. 



As there has been a tendency in recent years to associate the 

 Ophioglossece with the isosporous Lycopodhm^, it is necessary to state 

 briefly what is at present known concerning the gametophyte in the 

 latter group. Fankhauser^ discovered in 1872 the brown subterranean 

 prothallus of Lycopodium annotinum. The examples found by him were 

 lobed, tuber-like, and marked by numerous ridges and depressions. 

 Antheridia and fully formed sporophytes were found on them, hence the 

 prothallia must have been monoecious. In 1884, Bruchmann-> found 

 some much younger prothallia. These were of oval and flattened form, 



3. Trans. British Associ.-ition, Oxford Meeting, i8<)4- Structure of Mosses and Ferns, 1895. pp. 224-228 



4. Bot. Zeitung-. 1873. No. i. 



5. Bot. Centralblatt. Bd. i., 1885, pp. 23-28. 



