484 POPULAR SCIENCE MONTHLY. 



at rest. If tlie needle is placed beMnd the fish, it will swim directly 

 forward; if at the side or about the middle, it causes the fish to 

 swim directly forward or to turn and swim in a direction opposite 

 the origin of the disturbance. Younger specimens have, as yet, 

 no power over the direction of their progress; the wiggling of the 

 tail simply produces a gyration, with the yolk as pivot. 



A young blind fish, six months old, swims about in a jerky man- 

 ner, chiefly by the use of its pectoral fins. It keeps close to the 

 side of the vessel, usually with its back to the glass. (The aqua- 

 rium was a cylindrical jar three hundred millimetres in diameter 

 and three hundred millimetres high.) It perceives a stick thrust 

 toward it as readily as a seeing fish can. It always perceives from 

 whatever direction it may be approached, and will invariably dart 

 away a short distance, sometimes making sharp turns to avoid the 

 stick, and always successfully. It can be approached from the top 

 nearer than from the sides or from in front. It does not avoid 

 the sides of the aquarium, which it frequently strikes. It is a 

 bottom feeder; its intestinal canal is always partially full. 



A long series of experiments was made on Amblyopsis and 

 Chologaster to determine their reaction to white and monochro- 

 matic light. Without going into the details of these experiments, 

 it may be stated that Amblyopsis avoids the light, regardless of 

 the direction or the color of the rays. The same is true of Cholo- 

 gaster, except that they were positively attracted by the red rays 

 of the spectrum as against the blue. 



We owe the first observations on the breeding habits of Am- 

 blyopsis to Thompson, who states that a fish " was put in water 

 as soon as captured, where it gave birth to nearly twenty young, 

 which swam about for some time, but soon died; . . . they were 

 each four lines in length." Little or nothing has been added to 

 our knowledge of this subject since that time, but the highly inter- 

 esting supposition of Thompson that they were viviparous has 

 gained currency, and it is therefore unfortunate that in this respect 

 he was in error. 



Putnam adds to the above that, judging from some data in his 

 possession, the young are born in September and October, and 

 further along remarks that they are " undoubtedly " viviparous. 



The eggs are laid by the female in under her gill membrane. 

 Here they remain for perhaps two months, till the yolk is nearly 

 all absorbed. If a female with young in her gill pouches is handled, 

 some of the young are sure to escape. This was observed, and 

 gave rise to the idea that this fish is viviparous. Eggs have been 

 obtained as early as March 11th and as late as September, and the 

 indications are that the breeding season extends throughout the 



