334 Journal of Comparative Neurology and Psychology. 



points on the path where the specimen took flight are indicated 

 by a short cross Hne, and the position of the lamp is represented 

 by a dot. 



In the first trial the insect veered over constantly to the left, passed by the 

 lamp and went off from the table before it turned around. In the following 

 trials a marked tendency to turn to the left is also shown ; frequently the insect 

 makes one or more complete circus movements to the left before reaching the 

 light. At the eleventh trial its course is corrected for the first time by a turn to 

 the right side, but, instead of going straight up to the light, it performed a com- 

 plete circus movement to the left before reaching it. The next time the course 

 was corrected by a sharp turn to the right and the circus movement was dispensed 

 with. At the next trial the course was corrected in the same way, and at the 

 fourteenth attempt the insect deviated only slightly to the left side and then 

 turned to the right to reach the lamp. In the following ten trials it reached the 

 light by a nearly straight path. Whenever it began to turn away from the light to 

 the left it corrected its course by a direct turn in the opposite direction instead of 

 going around in a complete circle as at first. During the latter half of the experi- 

 ment the insect became more excited and walked to the light more rapidly and 

 with less hesitation and wavering. The experiment was discontinued at 12:10 

 P. M. and resumed at i P. M. The insect had not forgotten in the meantime 

 how to reach the light by the most direct means. In eleven trials it went to the 

 light in nearly a straight course, as is shown by the second series of tracings. 



The specimen was then placed with its left side towards the light. In each 

 of its successive trials it turned sharply to the left and went up to the lamp. It 

 was then placed with its right or blind side towards the light. In the first two 

 trials it turned sharply towards the light and went up to it. In the third trial it 

 first turned towards the light, but soon veered over to the left and went away 

 from the light instead of towards it. When placed again with its left side to the 

 light it no longer went towards it as before. It manifested a decided negative 

 phototaxis in fifteen successive trials. When placed facing the light, as in the 

 first experiment, it turned sharply to the left and went away from it for three 

 times in succession. Then a fit of positive phototaxis began to manifest itself 

 again. In the fourth and fifth trials it reached the light by an irregular course. 

 After this it went nearly straight to the light fourteen times. It was now allowed 

 to rest for an hour and a half, when it was experimented with again. At the first 

 trial it turned to the left, but corrected its course by a turn in the opposite direc- 

 tion and reached the lamp. In the second trial it went to the lamp in nearly a 

 straight line. At the third attempt, after it had gone nearly to the light, in an 

 almost straight line it turned away from it and went off in another direction. 

 A fit of negative phototaxis now began to assert itself and in the next thirty 

 trials it turned to the left and went away from the light. It vras now nearly 

 exhausted and could scarcely raise its body from the table. When near the light 

 it would move in an excited manner in an effort to get away from it, but when 

 it reached a darker region its movements became much slower, and it would 

 soon come to rest. The experiments were then discontinued until the following 

 day, when the specimen proved to be still strongly negative. After fifteen trials 

 wera made, in which it turned away from the light, except during a short fit of 



