The Gametophyte of Dipteris conjugata

1. Germination of the spore in Dipteris conjugata results in a plate, in a more or less irregular mass, or (more rarely) in a filament. 2. The mature gametophyte has a thick midrib and ruffled wings; it is similar to that of Gleichenia in appearance. No hairs are borne on the gametophyte. 3. The antheridium is of a primitive type with a wedge-shaped basal cell and a wall consisting of four to six additional cells. The cap cell divides once or twice, forming an opercular cell which is thrown off at maturity. The antheridium varies greatly in size, and the number of sperms may be considerable. One diameter of the antheridium may show five to eleven sperms. 4. The archegonium develops in the usual manner of the leptosporangiate ferns. The neck is straight and unusually long; it is directed forward on the younger parts of the gametophyte, but on the older parts it is directed laterally or downward. 5. Apogamy is of frequent occurrence. 6. The evidence given by the gametophyte of D. conjugata suggests a closer relationship to the more primitive ferns, particularly the Gleicheniaceae, than to the Polypodiaceae, and indicates that the family Dipteridaceae established on the basis of sporophytic characters alone is also justified by the structure and development of the gametophyte.