FIG. 50. 



FIG. 51. 



FIG. 52. 



FIG. 53. 



Fig. 50. Castor bean grown under equilateral illumination. 



Fig. 51. The same plant after some hours of slow revolution on a universal 

 axis. 



Fig. 52. The same plant after a few hours of equilateral illumination, following 

 the condition shown in Fig. 51. 



Fig. 53- The same plant after a few hours of one-sided illumination, following 

 the condition shown in Fig. 52. 



