60 SAKYO KANDA. 



the horizontal, so that their heads were all directed upward. 

 Meamvhile sea-water was poured, two or three times, over the 

 animals and the plate surface to prevent their moving before the 

 commencement of the experiment, and at the same time to get 

 them to stick tightly to the surface. When the desired number 

 of individuals had been so placed, the support was reversed, and 

 placed at the desired angle in the holding apparatus, so that their 

 heads were, now, directed downward. The animals being 

 negative to gravity, this procedure was necessary in order to 

 determine their movements of orientation in a desired time. 



Experiments were conducted either in sea-water in a glass 

 aquarium, or in air. To exclude the effect of light in either case, 

 a square box painted black inside was employed to cover the whole 

 arrangement described above. 



After the desired time for a particular experiment, the cover- 

 box was removed. Then the movements which the animals 

 had made were recorded (with detailed notes) as nearly as 

 possible as follows: A movement of 180 from the original was 

 designated as "oriented"; 90 as "horizontal"; and o as "ori- 

 ginal." If an animal was observed to have crawled downward 

 from the original place, it was recorded as positive to gravity. 

 It was noticed that some individuals did not crawl downward 

 quite vertically, but no discrimination as to these is made in the 

 tables. Quite a few individuals, that crawled horizontally, are 

 also arbitrarily classified under "horizontal," although such 

 movements are believed by the writer to have no great signifi- 

 cance. 



A question might be raised about middle spaces between 

 1 80 and 90, and also between o and 90. Such positions were 

 seldom observed; but if any were observed, they were recorded 

 as "oriented" at a position between 90 and 180; as "horizontal" 

 between 90 and 45; and as "original" between 45 and o. 

 Moreover, since quite a number of individuals would possibly 

 have become oriented if they had been given longer than one 

 minute, it might have been better to describe them as " orienting " 

 rather than "horizontal." The animals whose position was 

 specified as "original" should not be interpreted as indifferent 

 to gravity. They simply failed to respond to it during the time 



