﻿1903] 



EMBRYOGENY OF ZAMIA 



191 



GINKGO 



THUJA 



GINKGO 



qOo o 



CYCAS 



ZAM/A 



PINUS 



TAX US 



EPHEDRA 



CYCAS 



ZAMIA 



PODOCARPUS 



GNETUM 

 ANGI05PERMS 



p;:ju5 



Fig. 17. A series of diagrams to illustrate the extent of free nuclear division and 

 wall-formation; the shaded portions of the last four figures represent the region of 

 wall-formation. 



