1913] GOW—MORPHOLOGY OF AROIDS 137 

Fics. 34-39.—Richardia africana: fig. 34, immature carpel, containing developing 
ovule which is just beginning to show the anatropous character; fig. 35, primary 
archesporial cell; fig. 36, first nuclear division in formation of embryo sac; fig. 37, 
four-nucleate embryo sac; figs. 38, 39, mature embryo sac. 
