REACTIONS TO LIGHT IN LARVAE OF ASCIDIANS 



169 



opposite edge of the indentation (fig. 6, B). Here the tail 

 continued to vibrate, turning fairly regularly from side to side, 

 usually through an angle of about 30°, but occasionally sufficiently 

 to force the body toward the abocular side against the opposite 

 edge of the indentation. These observations were continued 

 until the specimen became attached and began to metamorphose. 



Fig. 6 Outline of Amaroucium pellucidum tadpole representing reaction to 

 increase in illumination. A, position assumed after decrease in illumination; 

 B, position assumed after increase in illumination; a, h, c, different positions 

 of tail assumed without change in illumination; v, vaseline. 



The results obtained throughout were in harmony with those pre- 

 sented above. 



Similar results were also obtained in the observations on the 

 specimen loosely held by the cover-glass. This specimen was 

 so held that it could not progress, but could swing laterally in the 

 plane of the slide in either direction around the central portion 



