MOVEMENTS OF GROWTH. 



405 



lings of Phaseolus in light and darkness respectively (see Figs. 

 134 and 135) we can also readily make out that the hypocotyl 



FIG. 132. Aerial part of 

 a seedling of Cucurbita 

 grown in the dark. 



FIG. 133. Aerial part of a seedling of Cucurbita grown 

 under normal conditions. 



remains very short even in darkness, while the epicotyl reaches a 

 much greater length than in light. The leaf-stalks of the prim- 

 ordial leaves are longer in darkness than under normal conditions ; 

 the blades of the leaves, on the other hand, only attain their normal 

 form and size in the light. Seedlings of Pisum and Vicia behave 

 like Phaseolus seedlings. The seedlings of Tropaeolum majus also 



