THE MORPHOLOGY AND AFFINITIES OF GNETUM 
l8l 
24. Scott, D. H. Evolution of Plants. London, Williams and Norgate, 1913. 
25. Strasburger, E. Die Coniferen und die Gnetaceen. Jena, 1872. 
26. Sykes. The Anatomy and Morphology of the Leaves and Inflorescences of 
Welwitschia mirabihs. Phil. Trans. Lond. 201 : 1910. 
27. Thompson, W. P. The Anatomy and Relationships of the Gnetales. L 
Ephreda. Annals of Botany 26: 1077-1104. 1912. 
28. Preliminary Note on the Morphology of Gnetum. Amer. Journ. Bot. 2: 
161. 1915. 
29. Thomson, R. B. The Megaspore Membrane of the Gymnosperms. University 
of Toronto Studies. 1905. 
30. Treub, M. Sur les Casuarinees et leur place dans le system naturel. Ann. 
Jard. Bot. Buitenzorg 10: 145-231. 1891. 
31. van Tieghem, P. Anatomic de la fleur femelle et du fruit des Cycadees, des 
Coniferes et des Gnetacees. Ann. Sci. Nat. V. Bot. 10: 269-304. 1869. 
16. Explanation of Plates II^ — VII 
Plate II 
Fig. I. Gnetum funicular e. Abnormal spiral strobilus. c, collar;/., ovulate 
flower. X 2. 
Fig. 2. G. gnemon. Abnormal staminate strobilus with many abortive ovulate 
flowers. /., ovulate flower; w., place of attachment of staminate flowers which 
have fallen. X 2. 
Fig. 3. G. gnemon. Part of similar strobilus at a younger stage. F., ovulate 
flowers; w., staminate flowers. X 5. 
Fig. 4. G. gnemon. Radial section of group of young flowers from staminate 
strobilus. /., abortive ovulate flower; pe., perianth; r., central rudiment of staminate 
flower; c, collar. X 200. 
Fig. 5. G. gnemon. Similar section of older group, m., microspore mother 
cells. X 200. 
Fig. 6. G. gnemon. Young microsporangium. e., epidermis; a., arche- 
sporium. X 400. 
Fig. 7. G. gnemon. Later stage, e., epidermis; p., primary parietal layer; 
s., sporogenous cells. X 400. 
Fig. 8. G. gnemon. Later stage, p.o., outer layer of parietal cells; p.i., 
inner layer. X 400. 
Fig. 9. G. gnemon. Microsporangium. ta., tapetum; w., mother cells. 
X 400. 
Fig. 10. G. gnemon. Microsporangium in stage of tetrad divisions. Letters 
as before. X 500. 
Fig. II. G. sp. jj. Young ovulate flower, pe., perianth. X 100. 
Fig. 12. G. sp. jj. Young ovulate flower, o.i., outer integument; i.i., inner 
integument. X 100. 
Fig. 13. G. sp. jj. Later stage of ovulate flower, h., hairs. X 50. 
Fig. 14. G. sp. jj. Later stage, i.i., inner integument elongating to form 
style; s., embryo-sac. X 100. 
