SEEDS. 153 



them with very pretty patterns ; and sometimes the 

 pattern is in colours, as in the seed of the common 

 campion (Lychnis). 



So also you will find a won- 

 derful variety as to the smooth- 

 ness or roughness of the seed 

 coats. Sometimes, like those 

 of the bean or apple, they are 

 smooth to touch ; but in many 

 seeds they are rough with 

 knobs, or furrowed, or winged, 

 or tufted, or rough with 

 hairs. 



And as to substance, see 

 how thin and membranous is 

 this testa or skin of the 

 walnut seed. Try that of the 

 bean. It has softened I dare 

 say in the water, and as you 

 peel off its coat you find that -,. 



Fl g- I35 A t hal f f bean 

 it is thicker and more seed, kn plumule of embryo, 



w its radicle, c one of the coty- 

 leathery than that of the ledons, s the testa. 



walnut. These differences evidently depend upon the 

 character of the pericarp in which the seeds are 

 enclosed. When the seed remains safely in the 

 pericarp until it begins to grow, then the testa is 

 likely to be thin and tender ; but if the pericarp is 

 soft so that the seed might be easily damaged, or if 

 it dehisces and the seeds are sent out to fare as best 



