CHAPTEii II 



THE ROUND OP PLANT LIFE 



The earliest stages of plant growth oecur in the seed, 

 hence this is an appropriate place to commence our study. 

 ^Ye will first consider 



Sectiox I. The Behavior of Seeds Toward Watee 



26. Seeds Absorb Water when placed in contact with 

 it. If we fill a. bottle with air-djy lieaus, then pour in 

 all the tepid water the bottle will contain, taking care 

 to shake out the air bubbles, and place the bottle in a 

 warm room, the beans will so<ni swell until they have 

 pressed each other cpiite out of shape, and no water -nill 

 be forced out of the bottle. This shows that the 

 beans have absorbed the water and have swollen in con- 

 sequence. This quality of absorbing water by contact, 

 at ordinary temperatures, is ]>( )ssessed to a greater or less 

 extent by most seeils. and indec-d liy nearly all air-dry 

 vegetable material. It is unnecessai'v that the seeds be 

 covered with water to enable them to absorb it. If in 

 contact with any moist medium, as a damp cloth or damp 

 earth, they ^^•ill absorb moisture and swell. 



27. The Rate at which Seeds Absorb Water depends 

 upon se\'eral conditions, as 



a — The xoater content of the medium with which they 

 are in contact. If we place one lot of beans in water, a 

 second in wet eaith and a third in slightlj' damp earth, 



