172 
AMERICAN JOURNAL OF BOTANY 
[Vol. 10* 
Figs. 1-18. Chromosome groups, alternately from female and male plants (Wis¬ 
consin stock), as indicated by symbols: I, from cell of dorsal surface layer of thallus; 2-8, 
from cells of interior of thallus; 9, from cell of wall of archegonium; 10, from cell of dorsal 
surface layer; 11, from cell of wall of archegonium; 12, from cell of interior of thallus; 13, 
from cell of papillate scale; 14, from cell of dorsal surface layer; 15, from cell of ventral 
surface layer; 16, from cell of interior of thallus; 17, from cell of dorsal surface layer; 18, 
from cell of ventral surface layer. 
Fig. 19. Chromosomes in cell of capsule wall, from greenhouse culture of Wisconsin 
stock. 
Figs. 20-24. Chromosomes of greenhouse plants grown from Florida stock: 21, 22, 
from cells of interior of thallus; 23, from cell of ventral surface layer; 24, from cell of dorsal 
surface layer. 
