212 



THE REPRODUCTIVE ORGANS 



seed-stalk and notice how it is attached. The seed-coat is 

 thin and brown ; and surrounds an embryo consisting, as 

 in the Bean, of two fleshy cotyledons, a radicle, and a 

 plumule. 



Compare with this the Acorn (Fig. 143). Here the 

 bracts are numerous, small, and form a compact cup. The 

 smooth fruit-coat encloses one seed, the embryo has two 

 large fleshy cotyledons. Such hard, dry, one-seeded fruits 



cu. 



Fig. 143. Fruit of Oak. i, Acorn with cupule ; 2, vertical 

 section of same ; c, cotyledon ; cu, cupule ; /, remains of flower ; 

 p, plumule ; Pe, pericarp ; r, radicle ; t, testa. 



are called nuts. The Sweet Chestnut and the Beech are 

 other examples. 



The fruit of the Buttercup (Fig. 144) consists of many 

 small, dry, one-seeded fruits, each the product of a separate 

 carpel, and attached to a somewhat swollen receptacle. 

 Each one is called a nutlet or achene. 



The Strawberry (Fig. 145) is very similar, but the 

 receptacle is slightly hollowed, and from its centre grows 

 a large, fleshy structure, in which the achenes are embedded. 



The Rose-hip (Fig. 146) differs from the above in that the 



