IN THE POLYPODIACEAE 373 
verse wall to form a filament of two cells, cut off by two oblique 
longitudinal walls, a branch cell on either side. Fic. 8, B, C, 
shows similar cases, however in Fic. 8, B, the second instead of the 
first prothallial gave rise to the branches. In Fic. 8, C, both the 
second and third cell each gave rise to a branch while the third 
cell of the filament continued the growth of the prothallium. In 
Fic. 8, D, the branch cell which developed from the first prothallial 
cell divided immediately to form the beginning of a plate of cells. 
The branched prothallium shown in Fic. 8, E, is in a much more 
Fic, 8. Branched prothallia of Camptosorus rhizophyllus L. AD, X 1253 
E, X75. 
Here a filament of four cells was 
advanced stage of development. 
his plate, early 
formed, then a plate of cells developed. From t 
in its development, a lateral branch was cut off which in turn 
formed an expanded prothallium. The original plate of cells 
- continued its growth into a broad prothallium which showed a 
decided tendency to branch at its apex. 
Asplenium Filix-femina (L.) Bernh.—The branched pro- 
distilled water cultures. Fic. 9, A, B, developed on the distilled 
water cultures and Fic. 9, C, on the inner surface of the pot 
