650 . THE AMERICAN NATURALIST. [Vor. XXXIX. 
ent distances, the light was moved so as to fall on different 
parts of each fish's body, eyes, tentacles, head, back, sides, etc., 
and there was no reaction to it by either hagfish. 
In regard to whether they could perceive objects or not, the 
first thing that I noticed about them was, that when swimming 
rapidly in crossing the tank from side to side, they would 
repeatedly strike the tank head foremost; and when one was 
taken from among the rocks and held for some minutes in the 
hand or dropped in a corner of the tank, it would proceed very 
cautiously, moving its head from side to side, keeping its tenta- 
cles outstretched, and apparently depending on them for knowl- 
edge of its surroundings. 
The two young hagfish referred to above I also tested for 
image perception, holding various objects close over their eyes, 
and bringing them nearer and nearer. They showed no reac- 
tion, no matter how near the object was, until the surface of the 
body was touched, when they jerked their heads away. These 
hagfish were neither sleepy nor sluggish, but were undoubtedly 
normal. The conclusion drawn is, that the perception of vari- 
ations of light and shade even when extreme, does not irritate 
the eyes. 
The evidence in regard to their hearing is just as negative as 
that concerning their sight, I was not able to find any noise or 
sound to which they would respond. 
In testing the sense of touch, very different results were 
obtained. If the tank is jarred, the fish immediately tighten 
their coils ; if they are touched suddenly they jerk their heads 
away. When they are swimming, and often when they are at 
rest, the tentacle crown is extended, and the tentacles, moving 
back and forth, sense the water currents or anything they may 
strike against. When swimming in search of anything, the ten- 
tacles are always on the alert, as tactile outposts or sentinels. 
The same two fish that were studied for light perception, 
were also experimented on for touch, and were touched lightly 
m. different places with a straw, a glass rod, and a fine needle. 
When touched lightly, fish A would not respond, but fish B 
would jerk itself away. Touching any part of the skin, whether 
of the head, over the €ye, on the back, on the side of the body, 
