07 



2. The antheridia are restricted to the lower surface of the 

 midrib, and are formed before the archegoiiia develop ; they 

 are much larger than those of other Marattiaceae, and in 

 this respect, as well as in the larger spermatozoids, re- 

 semble Ophioglossum. 



3. The archegonium resembles closely that of the other Ma- 

 rattiaceae, but is larger. 



4. The development of the embryo is similar to that of the 

 other Marattiaceae. Probably all of the organs, except the 

 foot, are of epibasal origin. As in the other Marattiaceae 

 the cotyledon emerges from the upper surface of the pro- 

 thallium. 



5. Both stem and root show a single initial cell, but it is 

 not tetrahedral in form and resembles more that of Mdrattia. 



6. The cotyledon in form and venation is very much like that 

 of OphiogJossum. 



, 7. The prothallium of the different species of Gleichenia agree 

 in the possession of a massive midrib. Most of the species 

 show a more or less marked development of leaf-like lobes, 

 this being especially conspicuous in G. laevigata. An endo- 

 phytic fungus is always present. 



8. Large prothallia with apparently functional archegonia, 

 are of common occurence. 



9. Antheridia are usually developed first, but continue to 

 form after the archegonia are mature. In all the species 

 examined, except G. laevigata, these were confined to the 

 ventral surface of the prothallium; -in G. laevigata they 

 occur upon both sides. 



10. The antheridia are much larger and more complicated than 

 in the species examined by Rauwenhoff. The wall-cells are 

 much more numerous and several hundred spermatocytes 

 may be formed. An opercular cell is probably always 

 present. The largest antheridia are found in G. laevigata, 

 the smallest in G. polgpodioides. Imperfect antheridia are 

 not infrequent in G. laevigata. 



11. The archegonia are often found in great numbers. They 



Ann. Jaid. bot. liuitenz. 2e Scm-. Vol. VIT. 7 



