NOTES OX DIPTEROCARPS. 



53 



Section through the petioles and plumule with the 

 lobes of the cotyledon round them, those of the placentar 



cotyledon enclosed. 



Section lower, one lobe of theplacentar cotyledon reach. 

 ing the surface. 



Section through radicle with the lobes of the cotyledons 

 round it, one quite enclosed. 



13 ? but they represent an extreme: for it is not usual for the 

 placentar cotyledon to be so fully enveloped by the other. Figure 

 14 is of a commoner condition. In it the placentar cotyledon 

 (at the level of the section, which is at one third from the apices 

 of the cotyledons) comes to the surface over about one fifth of the 

 circumference. Figure 15. which is of a different species, shows it 

 on the surface over one-third of the circumference. 



' " Figure 14, section of the embryo of Dipterocarpus comutus showing the 

 placentar cotyledon at the surface over one-fifth of the circumference, and the 

 outer cotyledon with three folds at the back ; figure 15, section of the embryo of 

 Dipterocarpus alatus, of Penang with the placentar cotyledon at the surface over 

 -one -third of the circumference. 



Figures 16. IT and 18 represent sections through the embryo 

 of a new Dipterocarpus from Selangor, with rather small fruits. 

 The placentar cotyledon is folded inside as described above. But 

 figures 19. 20 and 21 show in the same species, the different fold- 

 ing mentioned above as resulting in the cotyledons being curved 

 into an S.. where neither is inside the other. 



S. -folding was observed in Dipterocarpus fagineus, Yesque, 

 D. alatus of Penang, D. comutus, Dyer, and this new species. 



Figures 16—21, section through 



two embryos of Dipterocarpus, n.sp. 



Figs. 19 — 21, showing on the right 



the usual folding, Figs. 16-18, on 



the left a folding into the letter S. 



The embryo of Dipterocarpus fagineus was found folded as 

 in figures 22. 23, 24, 25, 26. and 27, and the embryo of Diptero- 

 carpus comutus as in figures 28, 29 and 30, a very similar arrange- 

 ment to that seen in figures 19. 20 and 21. 



R. A. Soc. No. 81, li 



