1915] HUTCHINSON—MALE GAMETOPHYTE OF PICEA 289 
nature of the first primary division. When the primary derivative 
is small and lenticular, it rapidly degenerates (figs. A-I and 20-26 
etc.); when the division is median or nearly so, each of the two 
cells formed has the power of repeated division, giving rise to a 
Fics. A-U.—A diagram to illustrate five types of development in male game- 
tophytes of Picea canadensis: P, primary cell; a’, a”, a’, the first, second, and 
third (potentially) antheridial cells; s, spermatogenous cell; sf, sterile cell; the 
dotted lines indicate origin and sequence; relative size is also shown; figs. A-E, 
primary divisions, first and second cells cut off evanescent, third by a secondary 
I I tog da sterile cell; figs. F-I, two primary divisions, 
second cell cut off from primary cell functions as antheridial; figs. K-M, first primary 
derivative functions as antheridial cell; figs. N-Q, two primary divisions give rise 
to two antheridial cells, repeated divisions of the first produce four free nuclei; figs. 
R-U, primary cell divides to form sister primary cells, each of which produces an 
antheridial group, a bi-antheridial gametophyte. 
divici 4 
