260 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
it is taken at once. This reflex usually (though not so invariably) follows a contact 
of meat upon any part of the dorsal fin, as well as the free filament. The reflex 
rarely fails when any one of the filamentous fins is touched by freshly cut meat. j 
After meat has been in the water for fifteen minutes or more it seems to lose its 
savor and the fins may be repeatedly dragged over it without calling forth a 
response, and the same is true of the barblet and lips. 
I tested the filamentous fins with a wisp of cotton wool on a fine wire, as I did 
the cat-fishes. It was rarely noticed at all by the pelvic fins, but at the first contact 
with the filamentous dorsal the fish reacted just as he did to meat with which he had 
been tested immediately before. Upon repetition, the response was soon discon- 
tinued. For a few tests the fish would pause, and perhaps back up slowly so as to 
smell the suspicious object or touch it with the barblet, but it was not taken into the 
mouth. After from two to ten tests no further attention was paid to the cotton, or 
the fish would pause a moment without backing up. This experiment was many times 
repeated in the course of the first day of its trial and daily thereafter for some time. 
If three or four hours intervened between two series of about twenty tests, the first 
one or two tests of the second series might be followed by an incomplete reaction, 
but after that usually no notice was taken of the cotton. The fishes apparently 
remembered the preceding tests. But if more than twenty-four hours intervened 
between tests, the process of training usually had to be gone over again. 
The fact that the hake does not appear to remember the difference between the 
pure tactile stimulus and the tactile plus the gustatory for so long a time as the cat- 
fish does is probably to be explained b} r the fact that the number of taste buds on 
the filamentous fins of the hake is much less than that on the bardlets of the cat-fish, 
and therefore the gustatory element in the sensation complex is doubtless much less 
in the hake. The whole course of the experiments indicates that the response is in 
fact much more strongly tactile in the hake. 
During the course of these experiments I often alternated bits of meat with the 
cotton wool, and at other times substituted cotton that had been soaked in clam juice. 
In these cases 1 always got the characteristic gustatory reaction by all of the filamen- 
tous fins, no difference being observable between the reaction to meat of clams or fish 
and that to cotton soaked in filtered clam juice. 
I also tested the hake with gelatin which had been soaked up in cold water. 
Shreds of the well-softened gelatin were fastened to the end of a wire and brought 
into contact with the body surface. The reactions were identical with those obtained 
with white cotton. The gelatin shreds are very nearly colorless and absolutely 
tasteless to my tongue. But to the sense of touch they are almost exactly the same 
as the bits of fresh clam meat with which most of these experiments have been con- 
ducted. The hake at first would take the bait when the filamentous dorsal was 
touched, but if the gelatin was taken into the mouth it woidd be immediately 
rejected, and after a few trials the fish would no longer respond to the stimulus. 
He acted in the same way when the pelvic fins were stimulated. Shreds of the 
softened gelatin falling through the water were sometimes noticed, but rarely taken 
into the mouth, and if so, were immediately rejected. Similar shreds lying on the 
bottom were neglected, even though the barblet and filamentous fins dragged over 
them repeatedly. 
