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SAKYO KANDA. 



crawled horizontally. Was this due "to the action of the film 

 of water," as Haseman claims? The question will be answered 

 after consideration of a few other experiments. 



Experiment B. The next series of experiments was of the same 

 nature as the above, but the animals were placed with their heads 

 upward instead of downward at the beginning. The results 

 given in Table VI. show that the starting position, that is, placing 

 the animal head downward or upward, at the beginning of the 

 experiment, makes a difference in the result. 



TABLE VI. 



GEOTROPISM OF SNAILS IN AND OUT OF SEA-WATER IN DIFFUSE DAYLIGHT AT 

 DIFFERENT ANGLES OF INCLINATION OF A GLASS PLATE. 



At beginning of experiments each head placed pointing upward. Table shows 

 results after one minute. 



Here, again, eleven individuals at the angle of 90 and five at 

 45 crawled horizontally beneath the surface-film of sea-water. 

 Besides these, six individuals at the angle of 90 and three at 45 

 "hesitated" at the surface-film when they reached it, and then 

 crawled upward through the film. This constitutes a puzzle for 

 the surface-film theory. But let us see further. 



Experiment C. Similar experiments were made in direct sun- 

 light. The glass plate in the aquarium was placed at 45, which 

 made it parallel to the rays of sunlight as nearly as possible. 

 The outside and bottom of the cylindrical glass aquarium were 

 surrounded by black cloth as already stated; and two sections, 

 a and b (see Fig. 3), separated within by the glass plate, were 



