GNETALES 



397 



The embryo cell divides transversely, and this is followed by a 

 succession of divisions in various planes until an ovoid mass of cells 



Figs. 448-453. — Ephedra trifurca: development of embryo; fig. 448, one of the 

 proembryos before the formation of the suspensor tube; X500; fig. 449, proembryo 

 with two free nuclei {s, of suspensor; e, of embryo) and a suspensor tube {t); Xsoo; 

 fig. 450, a later stage, showing suspensor (s) and embryo (c); Xsooj fig- 45 1, character 

 of the wall, nearly complete, which separates the suspensor and embryo; X 1,900; 

 fig. 452, division of embryo initial cell; s, suspensor; Xsoo; fig. 453, later stage of 

 embryo and secondary suspensor; XsSo.-r-After Land (23). 



is produced (figs. 452, 453). The basal ceUs of this group elongate 

 successively, forming a multicellular secondary suspensor, which 



