INFLUENCE OF EXTERNAL CONDITIONS ON GROWTH 



269 





B 



Fig. 122. — Two branches of broom, Genista anglica. C, 

 grown in dry air; B, in moist air. 



I 



<*k 



E I M 



Fig. 121. — Leaves of Tarax- Fig. 123. — Sempervivum. I, normal; II, grown in moist 

 acum. A, grown in very moist air; III, grown in darkness, 



atmosphere (actual length about 

 60 cm.). B and £', grown under 

 usual conditions (actual lengths 

 about 15 and 12 cm., respectively). 



