52 



NOTES ON DIPTEEOCARPS. 



When the fruit is ripe it falls as a shuttle-cock to the floor 

 of the forest and there without delay germinates. The embryo, at 

 fruit-fall, and if normal, is as in figures 3 and 4, the placentar 

 cotyledon being enwrapped more or less completely by the other, 

 the radicle extruding slightly from the basal lobes that the coty- 

 ledons possess, or just covered by them. 



Figures 3, an embryo of Dipterocarpus cornutus from the placentar side 

 and 4, from the back. In figure 3 trie edges of both the cotyledons are seen ; 

 in figure 4 a fold is seen in the upper part of the outer cotyledon. Nat. size. 



The way in which the placentar cotyledon in enwrapped, will 

 be adequately realised from the series of sections, figures 5 to 



Section of embryo of Dipterocarpus cornutus near the 

 a pices of the cotyledons. The placentar cotyledon only 

 comes to the surface at this level at the side which is above 

 in the figure. 



Section lower. The placentar cotyledon just comes to 

 the surface. 



Section lower. The placentar cotyledon is quite enclosed. 



Section lower, with the same appearance. The bundles 

 of the petioles of the cotyledons have not spread into the 

 j blades at this level. 



Section lower, at the junction thepetiole of the placen* 

 tar cotyledon with its blade. 



Neighbouring section to the last, the petiole free. 



Jour. Straits Branch 



