45 
and Helminthostachys zeylanica . 
the surrounding humus. The growth of the young prothallus 
and of the branches is apical, a four-sided initial being present. 
Rhizoids are absent, but the surface is covered with short 
unicellular hairs. 
%. A symbiotic Fungus is present in the internal cells of the 
prothallus. Repeated infection takes place through the 
unicellular hairs. 
3. The prothallus is monoecious, the sexual organs arising 
in acropetal succession. 
4. The antheridium originates from a single superficial cell. 
The mature antheridium is sunken ; its outer wall is one layer 
of cells thick ; the oval mass of spermatozoids is surrounded 
by a layer of flattened cells free from the endophyte. 
5. The archegonium is developed from a single superficial 
cell. Its neck, which consists of four rows of cells, hardly 
projects from the surface. The ovum and a binucleate canal 
cell can be distinguished in the central series. A basal cell is 
present. 
6. The embryogeny could not be completely studied ; the 
stage found showed a general agreement with other Ophio- 
glossaceous embryos. Young plants were not seen. 
Helminthostachys . 
1. The prothalli are subterranean and wholly saprophytic ; 
they consist of a lobed basal portion (vegetative region), from 
which a cylindrical process (the sexual region) arises : the 
growth is apical, by means of a single initial cell. Rhizoids 
are present on the vegetative region. 
3 . A symbiotic Fungus is present in the cells of the 
vegetative region ; it dies about the time that the sexual 
region begins to elongate, and growth is completed at the 
expense of the accumulated starch. 
3. There is an imperfect sexual differentiation ; the vegeta- 
tive region is larger and more strongly lobed, and the sexual 
region shorter and thicker in the female prothalli, than in 
those which bear antheridia. 
4. The antheridia, which originate from single superficial 
cells, are sunken. Their wall is in part two-layered, but the 
