178 BOTANICAL GAZETTE [SEPTEMBER 
Fic. 24.—Showing the stalk (sc) and body (bc) cells as well as prothallial 
cells (p:, p2) and tube nucleus (#). é 
Fic. 25.—The mitosis giving rise to stalk and body cells from the primary 
spermatogenous cell. 
Fic. 26.—A usual type of mature gametophyte, having four derivatives of the 
first primary prothallial cell (p,), four of the second (,), stalk (sc), and body (6c) 
cells, and tube nucleus (é); nine cells also usual (two #:, four 2, stalk, 
tube). ; 
sae 27.—Showing the prophase of the division of the first prothallial cell 
(pz) and what appears to be a “‘cell” (x) on the side of the body cell opposite to the 
stalk cell (se); no nucleus could be discovered in this “‘cell;’’ see text for ieee 
details. 
Fic. 28 .—Division of the microspore nucleus in P. nivalis; a peculiar seg- 
mented appearance of the spirem, which has about completed segmentation into 
chromosomes, is shown. 
Fic. 29.—A similar but younger spirem which has not yet begun to segment 
as the preceding one has done. 
Fic. 30.—Anaphase of the division resulting in second prothallial cell (pa) 
and antheridium initial. 
Fic. 31.—Late telophase of division of antheridium initial into primary 
spermatogenous cell and tube nucleus; this is the usual shedding stage of this 
species, with prothallials undivided. 
Fic. 32.—Metaphase of division of uilpacitions initial showing the twelve 
gametophytic chromosomes; see also jig. 27. 
Fic. 33.—Details of nucleus of primary spermatogencus cell of P. totarra 
Halli. 
