254 BULLETIN OF THE UNITED STATES FISH COMMISSION. 
As a rule the fishes swam in narrow circles close to the' bottom and for a lone - time 
failed to find the meat, though they seemed to be aware of its general position for 
they never circled far away. If the meat were very slowly moved across the aqua- 
rium the fish could be drawn in this way after it for a considerable distance, though 
the meat was never found unless in the course of their apparently aimless movements 
one of the fishes came in contact with it, when it was instantly snapped up. 
This aimless circling movement may be termed provisionally the seeking reac- 
tion , since it is so different from the characteristic movement made when the stimulus 
is in contact with the body — a sharp turn of the body and instantaneous seizing of 
the bait — which I shall term the gustatory reaction. Unfortunately, I have not had 
opportunity as yet to carry out extirpation experiments on Ameiurus to determine 
decisively the part played by the olfactory organ in this reaction. (Compare the 
experiments on the tomcod narrated below.) 
The fishes upon which these experiments were performed have unfortunately 
been lost. At the present time 1 have a fresh lot of Ameiurus fry under observation, 
and have already verified many of the conclusions reached with the first lot. But i 
this second collection of fishes has not, at the time when this report is submitted, 
been in captivity long enough to become sufficiently accustomed to their new sur- 
roundings to feed freely and fearlessly. After some months of further prelimi- 
nary observation, I hope to carry on experiments which may shed some light on the 
sense of smell in these fishes. But this must be reserved for a later report. A few 
subsequent observations are noted on pages 270-271. 
We must content ourselves at the present time, then, with the inference that 
the sense of smell plays at least a small part in these reactions, for the animals 
became slightly restless in the proximity of the stimulus, though they were not in 
contact with it; this, however, appears never to provoke a definite reaction of seiz- 
ing the food, but merely a vague reaction in search of food. On the other hand, 
physical contact with the irritating substance causes a definite .and precise reaction 
which is practically constant. This points either to touch or to taste. 
To test the relative part played by stimulation of these two sets of sense organs, 
the following series of experiments was performed. A half dozen fish in an aqua- 
rium were tested a score of times with fresh meat on the tip of a wire, as in the 
previous cases. The reaction was obtained uniformly, no matter what part of the 
body or head was touched. Half an hour after the close of these experiments a bit 
of cotton wool was wound around the tip of a wire and the fishes were tested with 
this exactly as they had been with the meat. For the first six trials the barblets 
only were touched. The fish in each case turned and seized the cotton as promptly 
as the meat had been taken. The cotton would be immediately dropped. After a 
few more trials the fishes would generally turn when touched, but would check their 
movement before the cotton was actually taken into the mouth. Several specimens 
were now tested on the trunk with the cotton. One or two turned completely around 
and took the cotton, but generally there was a slight movement only toward the 
cotton, which was checked before the cotton was reached. After a few further 
tests, the fishes would usually pay no attention to a contact with the cotton on the 
skin of the body and the reaction by the barblets became uncertain, until finally the 
cotton could be freely rubbed over the barblets or lips of some of the individuals 
without producing any response. 
