THE ORGAN AND SENSE OF TASTE IN FISHES. 
255 
These experiments were many times repeated, sometimes using' white cotton, 
sometimes red cotton, and sometimes fresh meat. The reaction was uniformly obtained 
with the meat. If at the close of a few experiments with the meat a minute pledget 
of cotton was substituted for the meat, there was feeble or no response from rubbing 
the body with the cotton, though upon touching the barblets the fish would usually 
turn and often would seize the cotton and drop it again at once. After several repe- 
titions, the fish became wholly indifferent to the cotton, no matter how it was applied, 
or they would if touched upon a barblet turn toward it without biting it. They were 
now again tested with bits of meat. This they took as eagerly and as precisely as 
before, showing that they were still hungry. 
After the interval of a day or two the fishes would still appear to remember the 
cotton, and I rarely, after the first trials, got a prompt “gustatory” reflex with the 
cotton. If they noticed it at all, they would turn slowly and touch it with the lips or 
a barblet in a tentative or inquiring manner, only to turn away again without taking 
it into the mouth. This deliberate movement may be designated, for reasons to appear 
immediately, as the tactile reflex , as distinguished from the instant seizing of food, the 
‘ ‘ gustatory reflex . ” 
These experiments seem to show that in the reactions to the meat, both from the 
barblet and from the skin of the body, the senses of taste and touch both participate. 
This is in accord with the known innervation of the skin and barblets, for all parts 
of the body surface receive general cutaneous (tactile) nerves, and all parts arc plenti- 
fully provided with terminal buds (taste buds) which are innervated by communis 
(gustatory) nerves. The experiments further suggest that these two sensory factors 
can be experimentally isolated by training. 
The fishes having become accustomed by brief training to make the simple reflex 
of seizing the food under the stimulus applied to any part of the barblets or skin, 
and doubtless utilizing both gustatory and tactile sensations, the gustatory factor is 
eliminated by the substitution of cotton wool for the meat. The tactile sensation 
alone proves to be sufficient to set off the reflex after the training previously given. 
The stimulus is, however, never followed by satisfaction and is soon given up, the 
fishes after further practice not reacting to the tactile stimulus alone. If, however, 
the gustatory sensation is added, by the substitution of meat for the cotton, the 
original reflex is given as promptly as before. This would seem to indicate that, 
while the tactile sensation alone is not sufficient to maintain the reflex, the addition 
of the gustatory element is sufficient, and therefore that the gustatory element is 
the essential element in setting off the reflex. This hypothesis was tested by an 
extensive series of experiments similar in plan to those last described. 
In general there was no noticeable difference between the reaction to the white 
cotton and that to the red, though in some cases, especially toward the end of the 
series of experiments, after the fishes had learned to pay no attention to white cotton 
when touched at any point by it, they would sometimes turn and touch the red 
cotton with the lips or a barblet, immediately to turn away again without biting the 
cotton as they did at first. The reaction is not the quick turn and instant seizing of 
the bait, which I have termed the “gustatory reaction,” but a more deliberate move- 
ment similar to what I termed above the “tactile reaction.” This occurred only 
when the cotton was in plain view at the time of the contact and is probably in this 
