338 Robinson . — Experiments on the Effect of External Stimuli 
A 
Fig. 6. A. Sowing of the conidia of Botrytis showing germ tubes growing away from the 
light of the window. The arrow shows the direction of the light, x 45. B. Control experiment 
carried out in the dark ; the germ tubes growing in all directions. x 45 
Fig. 7. Sporidia germinating in droplets of condensation water. All the germ tubes are 
directed out of the droplets which are indicated by the dotted lines, x 100. 
