THE ACORN AND ITS GERMINATION. 



13 



with a thin, brown, wrinkled, papery membrane, which 

 is its own coat the seed-coat, or testa (Fig. 2, t). The 

 extent to which the testa remains adherent to the seed, 

 or to the inner coat of the pericarp, and both together 

 to the harder outer coat of the pericarp, need not be 



C. 

 I 



FIG. 2. Sections of acorns in three planes at right angles to one an- 

 other. A, transverse ; B, longitudinal in the plane of the cotyledons, 

 (1) ; C, longitudinal across the plane of the cotyledons ; c, cotyledons ; 

 t, testa ; p, pericarp ; s, scar, and /, radicle ; pi, plumule. The radicle, 

 plumule, and cotyledons together constitute the embryo. The em- 

 bryonic tissue is at r and pi. The dots in A, and the delicate veins 

 ill E and C, are the vascular bundles. 



commented upon further than to say that differences in 

 this respect are found according to the completeness 

 and ripeness of the acorn. 



Enveloped in its testa and in the pericarp, then, we 

 find the long acorn-shaped seed, which seems at first to 

 be a mere horn-like mass without parts. This is not 

 the case, however, as may easily be observed by cutting 

 the mass across, or, better still, by first soaking it in 

 water for some hours ; it will then be found that the 



