8 J. K. WODSEDALKK 



undesirable features of the environment. Then, six specimens 

 in separate dishes were placed at one end of the room and sub- 

 jected to four daily disturbances. In another part of the room 

 were three individuals undergoing one disturbance each day; 

 and some distance away were three more, disturbed but once 

 in three days. In separate dishes scattered among these were 

 six other individuals undergoing no disturbance whatever. 

 Careful observations were made and detailed records of the 

 behavior of all the specimens were kept. 



Tables V and VI suffice briefly to show the results obtained 

 with two of the specimens. Their behavior was characteristic 

 of more than half of the 18 nymphs observed in this manner. 

 The letters A, B, C, and D, designate the behavior displayed 

 on the first, second, third, and fourth daily observations re- 

 spectively. Each one of the three columns is intended for a 

 particular form of behavior displayed by the nymphs, and the 

 letters indicating the behavior manifested during the four daily 

 observations are placed in the columns accordingly. Omission 

 of a letter means that the nymph was not easily disturbed on 

 that occasion. In the first column are recorded the cases of 

 indications of fear only when the specimen was slightly dis- 

 turbed with a dissecting needle. In column II are given the 

 cases of signs of agitation when a hand w T as passed back and 

 forth above the dish, and in the last column are indicated the 

 signs of fear displayed by the specimen in the way of swimming 

 about in an excited manner when I appeared before the enclo- 

 sure. For example, on March 31, on the first observation, 

 which was in the morning, specimen number one showed signs 

 of fear only when the water near it w T as disturbed with a dissect- 

 ing needle, and hence (A) w r as placed in the first column. On 

 the second observation, which w T as at noon, the nymph began 

 to swim about in an agitated manner when my hand was moved 

 back and forth over the dish, thereby making a place for (B) 

 in column two. On the third observation, which was about 

 six o'clock in the afternoon, the insect displayed indications of 

 fear when I appeared before the enclosure, and so (C) naturally 

 fell in column three. On the last observation on that day, 

 which was late at night, the nymph again showed signs of fear 

 when a hand was moved back and forth over the dish, which 

 caused (D) also to be in the second column. 



