8 



EXPERIMENTS \\ITH PLANTS 



that at frequent intervals. Notice whether soaking af- 

 fects the size, color or texture. Does the cover wrinkle: 



14. A Bean placed in water, showing successive stages in the process of wrinkling; the 

 wrinkling indicates where the water enters and how it spreads inside the cover. 



if so, where does the wrinkling commence, arid in what 

 direction does it progress? (See Fig. 14.) Does this in- 

 dicate where water first enters the seed ? What causes 



the wrinkles ? Why do 

 they disappear after a 

 time I Do the covers 

 appear to hinder the 

 water from being ab- 

 sorbed by the germ? 

 Consider the appar- 

 ently water -proof 

 covers of the Castor- 

 bean, Buckeye, etc. 

 Would it not be an 

 obvious advantage to 

 have openings in the 

 cover through which 

 the water might enter 

 more rapidly? Are 

 ^- there such openings 



15. A method of determining whether openings exist in 



the seed-covers. 



