6 4 



EXPERIMENTAL PLANT PHYSIOLOGY. 



EXPERIMENT 78. 



MOVEMENTS OF STAMENS. 



Touch stamen-filaments of Centaurea, Carduus, or Cichorium. 

 The filaments contract. 



FIG. 60. 



Tendrils of Bryony. (Kerner.) a, young tendrils ; b b, nearly mature and 

 very highly irritable ; c <-, two tendrils which have intertwined. 



EXPERIMENT 79. 



CURVATURE OF TENDRILS. 



Touch a tendril of the Passion-flower, Bryony, or Squash on 

 the concave surface near the tip with a pencil and observe carefully. 



