310 MR. W. GRIFFITH ON THE GENUS GNETUM. 



EXPLANATION OF THE PLATES. 

 Tab. LV. 



Fig. 1. Very young ovule of Gnetum scandens viewed on its upper or posterior surface, which is observed 

 to be cleft longitudinally. 



Fig. 2. Second envelope, showing its divided apex, the laciniae of which are connivent. This coat is 

 visible at a in fig. 1. 



Fig. 3. Nucleus of the same, both coats being removed. 



Fig. 4. Posterior view of an ovule (long before the dehiscence of the anthers), showing the longitudinal 

 cleft, the margins of the upper part of which are in this case, and indeed generally at a period 

 rather later than that to which figs. 1-3 refer, in apposition ; part of the second coat is visible 

 at a, and another portion projects through the apex at b. 



Fig. 5. Inferior or anterior view of the same ovule, along which no fissure is visible. 



Fig. 6. View of the inner or second coat, showing its irregularly-divided apex. 



Fig. 7- Nucleus highly magnified (the coats removed), showing the depression at the apex and the 

 central conical elevation. 



Fig. 8. Apex of the nucleus ; the conical elevation appears emarginate. 



Fig. 9. Ovule of G. Brunonianum ; no fissure through the outer coat except at the apex. 



Fig. 10. Longitudinal section ; the apex of the inner coat is visible on a level with that of the outer coat. 

 A central cavity enclosing the remains of a sac is visible within the nucleus. 



Fig. 1 1 . Transverse section of the same. 



Fig. 12. The inner coat, with part of the outer remaining at the base. This figure shows the narrow, 

 deeply-divided apex of this coat. 



Fig. 13. Nucleus, with half the bases of the coats remaining. 



Fig. 14. Ovule of G. Brunonianum some time after the fall of the male flowers ; at its apex are visible 

 several projecting processes of cellular tissue. 



Fig. 15. Vertical section of the same, showing that a new coat has been developed between the inner (now 

 second) coat and the nucleus. This coat is prolonged beyond the nucleus into a cylindrical 

 tube, the mouth of which is divided, and projects slightly beyond the opening through the apex 

 of the outer envelope. The second coat is now tinged with yellow. 



Fig. 16. Ovule with outer coat detached; the tubular prolongation is seen to project considerably beyond 

 the opening in the apex of the second coat. The timbriee of the extremity of the tube have not 

 yet become expanded. 



Fig. 17. The same with the second coat removed, showing the third coat throughout. 



Fig. 18. Vertical section of an ovule of G. Brunonianum, showing the parts in situ. The apex of the 

 second coat is preserved entire : the correspondence of the apex of the nucleus to the commence- 

 ment of the tubular prolongation, the expanding fimbriae of this, and the adhesion with the base 

 of the nucleus, are represented. The tube is not much sphacelated at this period. The termi- 

 nations of the vascular fascicles at the base of the nucleus are shown. 



Fig. 19. Transverse section of the ovule near its apex, showing the two envelopes and a portion of the 

 tubular prolongation. 



Fig. 20. Vertical section of the whole of the third envelope and the nucleus. At the base of the nucleus 

 appear the terminations of the vessels ; but this is only apparent, the vessels being cut through as 

 they diverge outwards to pass into the envelopes ; none exist in the nucleus. 



fig. 21. Vertical section of the immature fruit of Gnetum apiculatum, some time after the fall of the 



