SEED-BEARING PLANTS 
407 
without undergoing any resting period, until the new sporo- 
phyte has emerged from the seed and become established 
FIG. 302. Zamia Jloridana. a, free nuclei of proembryo; X 16; b, 
tissue at base of proembryo; X 24; c, differentiation into suspensor and 
embryo; X 29; d, young embryo showing long suspensor, natural size. 
(After Coulter and Chamberlain.) 
in the soil as an independent plant (Fig. 303). In its early 
stages the embryo derives its nourishment as a parasite 
from the female gametophyte (prothallus, or endosperm). 
