372 



There does not appear to be any regular association of the 

 movements of the anterior and posterior extremities ; they are 

 not moved alternately, but quite independently of each other's 

 motions. 



They seize living worms eagerly, and suck them down, if 

 small, with a single sudden swallow ; if the worm be large, it is 

 swallowed by repeated suctions, the teeth preventing its escape ; 

 the act of suction may be seen by the movements of the impurities 

 in the water, as it is drawn in and afterward expelled. They 

 often miss the worm ; sometimes it may be too far off, but at 

 others so close to them that it seems as if their vision must be 

 imperfect. They will not eat a dead worm, unless J;hey have 

 been kept without food for a considerable time. 



They are most active at night, during which they move very 

 rapidly, throwing themselves nearly out of water. 



The branchiae shrink both in length and diameter, and assume 

 instead of a crimson an iron or slaty gray color ; the extreme 

 change from expansion to the smallest size, and vice versa, often 

 takes place in a minute or two. 



In the water of their native lake they were infested with a 

 white parasitic worm, which attached itself very firmly to the 

 skin and to the gills ; in the Cochituate water they have been 

 entirely free from these. 



They have a habit of passing the fore feet alternately through 

 the gills from above downward and forward, several times in 

 succession, as if to clear these organs from particles of dirt and 

 impurities floating in the water. 



They almost always remain at the bottom of the vessel in the 

 daytime, though occasionally they remain for a few minutes at a 

 time suspended in the water with the nasal openings above the 

 surface. 



It is frequently noticed that after uncommon activity, and 

 sometimes in the daytime, their excrement is seen in the water, 

 as if these violent contortions of the body assisted in the perform- 

 ance of this act. 



A few weeks ago, when they had eaten nothing for five 

 months, four living minnows, one two inches long, were put into 

 the vessel with them ; of course, they . were very hungry, but 

 much to his surprise, three of the four fish were swallowed be- 

 fore the expiration of fifteen minutes, and among them the 



