Fig. 119. Ontogeny of the monocotyledonous embryo, Juncus bufonitis. 1, mature 

 8-nucleate embryo sac; 2 to 19, successive stages in development. First divisions, 

 transverse, separating the embryo proper from suspensor; 4 to 12, both parts increase 

 in size; 14 to 19, basal suspensor cells abort and are detached, cells of micropylar 

 end increase greatly; root-meristem differentiation in 19. arU, antipodals; E, embryo 

 proper; ep, epidermis; np, polar nuclei; S, suspensor; sd, suspensor cells early 

 detached; sp, persistent suspensor cells; sy, synergids. {After Laurent.) 



316 



