26 



PLANT RELATIONS. 



Fk;. 3(1. A spray of raupic, slicw iii^ the adjustmeut of the k-aves in size and position 

 of blades and ]t'nc;th of petioles to secure exposure to light on a horizontal stem.— 

 After Kkrxek. 



etc.^ as to give ample evidence of the eit'ort put forth by 

 plants to secure a favorable light-relation for their foliage 



Fig 21 Two plants showing ad]U8tment of leaves on a horizontal stem. The plant 

 to the left is nightshade, in which small blades are fitted into spaces left by the 

 large ones. The plant to the right in Srlaginclla, in which small k'a\'i-s are dis- 

 tributed along the sides of the stem, and oL'.icrs are displayed along the upper sur- 

 face.— After Kerner. 



