MONOCOTYLEDONS PALMS 



59 



Here we see the digestion of the hard endosperm 

 by the cotyledon going on, for this hard white sub- 

 stance is mostly solid cellulose, but from the tip of the 

 cotyledon is secreted a substance which changes it 

 into another kind of carbohydrate sugar which being 

 soluble can be absorbed by the plant. 



Canna seedlings can more quickly be raised, and 

 in them the structure is very much the same only 

 that the cotyledon is very short, consisting in fact 

 only of a round head inside the seed (absorbing the 

 endosperm exactly as does that of the Date) and a 

 very short stalk outside it. Looking at it by itself 

 one would never call it a leaf nor even a coty- 

 ledon but the case is after all, not so very different 

 from that of the Pea only that in the Pea there 

 are two cotyledons and they have already, before 

 the seed was ripe, absorbed the endosperm, a work 

 which in the Canna seed is begun only with the 

 germination. 



8. Procure a 

 cov - Palmyra nut that 

 has been planted 

 and has begun to 

 germinate. There 

 is no micropyle 

 visible, for the seed 

 is really enclosed 

 inside the hard 

 outer shell, so the 

 FIG 13 micropyle cannot be 



GERMINATING FRUIT OF THE PALMYRA S66n. The germi- 



PALM BORASSUS FLABELLiFER nation is apparently 



cot. 



