NOTES ON D1PTEBO0AKPS. 



163 



figure 7. If there happens a most unlikely occurrence in nature, — 

 that the cotyledons cannot be pulled out, and the root does not hold, 

 the latter by the straightening of the hypocotyl is raised up into 

 the air, and held. 



The cotyledons at this time move so as to become nearly 

 horizontal and stand thus unless as not seldom happens their lobes 

 engage, when they remain face to face as figure 6 indicates. 



Figs. 5 and '6, Shorea leprosula 



the root being placed in the 



earth. 



A glance at figure -I shows than any impression of the placentas 

 will be on the lower surface of the inner cotyledon only, but that 

 impressions of the radicle may be on the lobes of both. In figure 

 5 the impression of the placentas is seen crossing the lobes of the 

 inner cotyledon : and in figure 8 the impression of the radicle may 

 be observed. 



Fig. 7. Shorea leprosula, reduced to 

 J, at the expanding of the first leaves, 



Figure 6 shows that the outer cotyledon retains more of its 

 humped shape than . does the inner cotyledon : and it is the 

 straightening of the inner cotyledon which more than anything 

 else appears to burst the fruit wall, — an interesting slight differen- 

 tiation of function. 



R. A. Soc, No. 76, 1917. 



