1908] COULTER— GNETUM GNEMON 4o 



Fig. 3. — Further development of pavement tissue; vacuolation of the sac. 

 X250. 



Fig. $a. — An ovule, showing general relation of regions shown in Jig. 3; the 

 tip of the nucellus has broken down (the only indication of a pollen chamber). 

 X40. 



Fig. 4. — Further development of pavement tissue and embryo sac (probably 

 fertilization stage). X220. 



Fig. 4a. — An ovule, showing relation of regions shown in Jig. 4. X40. 



Fig. 5. — Later stage of embryo sac (possibly still in fertilization stage), with 

 grouping of nuclei in the antipodal region, where tissue formation probably 

 begins; beginning of disorganization of pavement tissue. X210. 



Fig. 5a. — An ovule, showing relation of regions shown in Jig. 5; also the 

 curious disorganization of cells and infolding of the epidermis in the nucellar 

 beak. X40. 



Fig. 6. — Tip of seed; small amount of tissue of nucellar beak not destroyed 

 by endosperm; differentiation of central and peripheral regions of endosperm, 

 the former having advanced into the center of the nucellar beak and spread 

 laterally, resulting in crushing nucellar tissue against the encroaching peripheral 

 region of endosperm; sections of two suspensors shown. X40. 



Fig. 6<z. — Mature seed invested by the fleshy "perianth;" outer integument 

 differentiated into outer fleshy (white) and stony (black) layers; inner integu- 

 ment forming the micropylar tube; at apex of nucellus is indicated the remains 

 of the nucellar tissue (shown with greater magnification in Jig. 6). X2. 



Fig. 7. — A proembryo, showing the branching, suspensor-like elongation of 

 the egg, with free nuclei and cleavage walls; also the embryonal cell containing 

 a nucleus and numerous starch grains; sections of other suspensors shown, 

 and also a small portion of the undestroyed tip of the nucellus. X40. 



Fig. ja. — Outline to show the relation of parts illustrated by Jig. 7. X3. 



Fig. 8. — Beginning of embryo formation by the embryonal cell, showing free 

 nuclei and the beginning of a cleavage wall; a cleavage wall in the suspensor 

 also shown. X250. 



Fig. 9. — Section of later stage of embryo, showing free nuclei, cleavage 

 walls, and the beginning of small-celled tissue at one side. X210. 



Fig. 10. — An embryo reconstructed from serial sections, showing free nuclei 

 cleavage walls, and the beginning of uninucleate cells. X140. 



