152 



cell in transverse section is three-sided, as in 0. vulgatum, 

 (which is most likely) or four-sided, as in 0. pendulum, In the 

 specimens under consideration antheridia were more numerous 

 than archegonia, although several of the latter were present. 

 The antheridia arise, in general, in acropetal succession, but 

 it is likely that secondary ones may be formed among the 

 older ones; at least, this seems to be true. The archegonia are 

 scattered among the antheridia without any definite order. In 

 some specimens examined — especially in the larger forms 

 shown in Figure 23 — old archegonia were formed in great 

 numbers, many more than antheridia. In some of the specimens 

 examined, however, a great part of the prothallium was quite 

 destitute of either archegonia, or antheridia, and in this respect 

 they differ markedly from any of those figured by Mettenius 

 or Bruchmann for O. pedunculosum or 0. vulgatum. 



All of the specimens collected at Buitenzorg showed a greater 

 or lesser number of rhizoids both at the base and along the 

 fertile branch (Figs. 25 — 26). In the more slender forms, however, 

 these rhizoids were few. They were in some cases two-celled 

 (Fig. 53) but usually consisted of a single elongated cell 

 (Fig. 52). Not uncommonly there could be seen within the 

 penetrating filament of the mycorhiza (Fig. 51) as has been 

 described for other species of Ophioglossum, as well as for 

 Botrycliium and Helmintliostacliys. The rhizoids are much longer 

 relatively than in 0. pendulum., and the two-celled ones resemble 

 somewhat the multicellular hairs found in Botrycliium. Ac- 

 cording to Bruchmanm, the rhizoids are quite absent from the 

 prothallia of 0. vulgatum. The endophyte is most abundant in 

 the tuber, but extends into the branch, where it occupies the 

 layer outside of the axial tissue which remains nearly or 

 quite free from the endophyte. According to Mettenius, the 

 prothallia often grow above the surface of the earth, when 

 they become more or less flattened and sometimes divided into 

 several small lobes. In such cases chlorophyll is developed, but 

 Mettenius was unable to note any further development of these 

 green lobes. Bruchmann also demonstrated the development of 



