XOTES OX DIPTEBOCABPS. 



55 



After reaching the ground the radicle is extruded from the 

 apex of the fruit without any well defined cracks spreading down 

 the fruit wall; it is thrust out by the elongation of the petioles 

 of the cotyledons as figures 34, 35, 36 and 37 indicate, and grow- 

 ing, exhausts the cotyledons of the nutriment stored in them, with- 

 out the development in them of any visible change. They do not 

 part in any way nor develop chlorophyll. Why has the genus 

 Dipterocarpus thin cotyledons, so much broader and more leaf-like 

 than is usual in the order, without any function attached that 

 belongs to the thinness of leaves? Their elaborate folding is a 

 consequence, of their size. Their surfaces which are morphological- 

 ly upper surfaces are very uneven. Why? They fit so tightly 

 together, that slipping over each other would seem impossible; but 

 the morphologically lower surfaces are smooth, as the drawings 

 indicate, and obviously one part slides over a.nother in growth. 



Figures 34-37, Seedlings of: — 



(34) Dipterocarpus Scortechinii 



(35) D. crinitm. 



(36) D. Kerrii. and 



(37) D. gran&iflorus 



All about nat gsize. 



Dipterocarpus produces after the cotyledons first a pair, and 

 then alternating leaves, the first of the alternating leaves is not 

 crowded onto the pair, at any rate not in D. Scortechinii King, 

 D. fagineus, Yesque, D. cornutus, Dyer, D. gratidiflorus, Blanco, 

 D. dlatus of Penang, D. crinitus, Dyer, nor D. Kerrii, King. 



R. A. Soc, No. 81, 1920. 



