144 C. H. TURNER. 



ward to e. It moves across to / and back to the post. After 

 ascending the post a short distance, it returns to e, passes along 

 e to /, climbs down / to its end and makes exploring movements. 

 It then ascends / to e, passes along e to the post and ascends it 

 to the band G. After making exploring movements, it descends 

 to e, passes along e to f, where it rests several minutes (in the 

 bright sunlight). It then descends / to its end and reascends it 

 to e. Then- descending /, it passes across to c, passes along c to b 

 and then retreats as far as e. It makes three trips back and forth 

 between e and / and then passes from e to the post, and up it to 

 band G. Avoiding the band, it encircles the post about three 

 fourths its circumference and then falls to the ground. 



With the tent-caterpillars these experiments were conducted 

 either in the shade, or in shady places that were spotted with 

 sunlight that had filtered through the trees. With many of the 

 others the experiments were conducted in the bright sunlight. 

 An accerelation of movements and an apparent tendency to 

 climb or descend the shady side of the post were the only dif- 

 ferences noted in the behavior of the caterpillars under these 

 conditions. 



EXPERIMENTS WITH A HORIZONTAL MA2E. 



The maze used has (Fig. 3) been fully described in Vol. XXV, 

 pp. 348-349, of the BIOLOGICAL BULLETIN. A cardboard incline 

 thirty inches long and two wide connected one of the interior 

 alleys of the maze with the supporting table. Eight inches of 

 this incline extended above the maze (Fig. 3). This gave each 

 caterpillar that arrived at the incline a choice of two pathways; 

 one passing obliquely upwards, the other obliquely downwards, 

 The maze was placed in an out-door insectary, all the light of 

 which came through the netting covered north side. In the 

 earliest experiments two caterpillars were used at a time, and 

 they were so located that they would be forced to approach the 

 incline from opposite directions. Later, when attention was 

 focused upon the behavior of the caterpillar when coming in 

 contact with the incline, twelve to fifteen insects were used at a 

 time; and they were placed on various parts of the maze. 



Although the insects displayed great individuality, the be- 



