THE PISTIL. 



121 



EXERCISE LV. 

 Monocotyledons and Dicotyledons. 



A MONOCOTYLED'ONOUS embryo has one cotyledon or 

 seed-leaf (Fig. 376). 



A DICOTYLED'ONOUS embryo has two cotyledons or 

 seed-leaves (Fig. 377). 



These are long, hard words, hard to pronounce and 

 hard to spell. But they are very necessary words in de- 

 scribing seeds. 



Go over the seeds you have planted, and point out the 

 dicotyledons. Find the two thick leaves that were packed 

 within the seed-coat when the seed ripened. 



Are any of your seeds monocotyledonous ? If so, which ? 



Figs. 376 and 377 were drawn from plants that had 

 grown a little. When your seeds have also grown a little, 



Cotyledon. 



Cotyledon. 



FIG. 376. 



FIG. 377. 



compare them one after another with these pictures. 

 Look at your young bean-plant. Find the first node 

 above the cotyledons. How many leaves are growing 

 there ? how many at the first node of the corn-stem ? how 

 many in each of your growing seeds ? 



