1. The reducing sugars remain constant throughout stimulation and response. 2. The hydrolyzable sugars increase on the convex side at the expense of the polysaccharides as response takes place. 3. The total sugars are constant until beginning of response, when the sugars of the convex side become greater. 4. The osmotic pressure increases until visible curvature has taken place. At the end of the reaction both flanks show the same osmotic pressure, which, however, is greater than that of the normal shoot. 5. Respiration of the geotropically stimulated root is greater than that of the unstimulated organ. 6. The rate of respiration of the convex side of the geotropically stimulated shoot is greater than that of the concave side throughout the period of perception and response. 7. Respiration decreases as the time of stimulation increases. 8. The steps, in point of time, of the chemical changes that take place in a geotropically stimulated shoot are: (1) increased respiration, (2) increased acidity (18), (3)...