Xll 



INTRODUCTORY LESSONS, 



q h 



a. Section oi a seed of Paeonia Brownii, showing the small emb-yo at the lighc .n the copious albu> 

 men. 6. The embryo removed and the cotyledons separated, c. The germinating peed d. Thr "ame, 

 with the seed coats removed t > show the leaf-like cotyledons, e. Plumule hud, or veal end or ,ne uiv 

 ward- gi-o wing stem. /. The first plumule leaf as it appears above ground, the terminal bud yei dormant 

 under ground, g. Peed of Pinus Sabiniaua (Digger, Willow, or Nut Pine) soon after it acpears above 

 ground, h. Same, with the seed coats removed to show the 14 cotyledons. See Figc 9, p. vi: 



You must have wondered why the cotyledons of a bean, which 

 never become leaf-like, should appear above ground. It is equally strange 

 that the albuminous seeds of the peony should behave in the reverse 

 way. As shown in the cut (a and b), the embryo is very small. In 

 germination the plumule comes up while the cotyledons become decidedly 

 leaf-like, and fill the shell which has been emptied of its albumen to feed 

 them and the plumule. These thin, veiny seed leaves could certainly do 

 better w^ork above ground than those of most lupines, yet they never come 

 up. There is another curious thing about the growth of peonj'- seeds, 

 which you may try to discover. 



"When the buckwheat and cotton seeds have begun to sprout, 

 you can study their embryos. Note how the thin, broad cotyledons of 

 the former are folded once and rolled up with a layer ot snow-white 

 starch; and how the speckled seed leaves of the latter are folded along 

 the center, then outwardl}^ back, and finally crumpled endwise to make 

 them fit coats too short for them. Maple seeds have curiously crumpled 

 and folded cotyledons. Indeed, all seeds have interestiug lessons to 

 teach us. 



Germination of Monoeotyledonous Seeds. Tlie seeds named 



