REACTIONS OF AMBLYOPSIS TO LIGHT. 323 



In the same paper Eigenmann records the action of a colony 

 of Amblyopsis in an open pool. " During the bright part of the 

 day, the fishes always remain under the rocks at the bottom. In 

 the morning and evening and at night they could be seen swim- 

 ming about in various parts of the pool." At Mitchell, near the 

 entrance of one of the caves, is a small pool, the bottom of which 

 • is covered with rocks. I found two fishes in this pool. They 

 were probably washed there during times of high water, as the 

 water runs from one cave to the other at such times. Later, I 

 put two more fishes into the pool and as I was making daily 

 trips to the cave I often noticed them swimming about near the 

 surface. The pool was not in the direct sunlight but the sun 

 reached it, in patches, between twelve and one o'clock, and I took 

 a number of observations at this time. I watched the pool for 

 15 minutes at a time and out of 13 observations made on 13 dif- 

 ferent days was able to see from one to three fishes ten times out of 

 the thirteen. Sometimes they came out only to go immediately 

 back under the rocks, but they often remained at the surface from 

 five to ten minutes. Apparently this seems to conflict with my 

 former experiments, but such is not the case, because under no 

 condition did the fishes remain in the dark all the time. I do 

 not mean to say that in the pool the fishes remain in the light 

 more than in the dark, but that they do come out at times even 

 in the brightest part of the day. 



Conclusions. 



1. Amblyopsis is negatively phototropic. 



2. The young are more sensitive to light than the adults. 



3. The young deprived of eyes are as sensitive as those with 

 eyes. Hence the eyes play no part in their reactions. 



4. They seek the dark regardless of the direction of the rays. 



5. When stimulated with a light focused to a point they seem 

 to be equally sensitive on all parts of the body. 



6. They are positively geotropic. 



7. They are photodynamic. 



8. These fishes are sensitive to light of low intensity and this 

 sensitiveness increases as the intensity of the light increases. 



