GNETALES 



395 



ently. To them the freed nuclei of the jacket cells appeared to fuse 

 in pairs and to form the functioning proembryonal cells; in other 

 cases the jacket cells of either layer were thought to function directly 



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446 



447 



Figs. 446, 447. — Ephedra trijurca: the proembryo; fig. 446, upper end of egg, 

 showing a group of spindles derived from the second male cell; just below are numerous 

 small cells which have come from jacket cells that have wandered into the egg, or from 

 the division of non-functioning proembryonal cells, or from both; farther down are 

 two functioning proembryonal cells; fig. 447, three of five functioning proembryonal 

 cells; jacket nuclei in the egg cytoplasm; free masses of cytoplasm; also masses of 

 cytoplasm remaining after the proembroynal cells have been carved out; X500. — 

 After Land (23). 



as proembryonal cells, in which case there had been migration of 

 nuclei from adjacent jacket cells and nuclear fusion. 



The non-functioning male cell enlarges and occupies the extreme 

 upper part of the egg, a space previously filled by the adjacent jacket 



