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BULLETIN OF THE UNITED STATES FISH COMMISSION. 
between cotton wool and cotton dipped in clam juice and between sea water and clam 
juice applied with a pipette, etc. The operated fish would locate a concealed bait by- 
means of the pelvic fins exactly as the normal fish does, and he would similarly 7 root it 
out and eat it. In short, the gustatory reflexes, so far as I have observed them, were 
absolutely unmodified by the operation. That the olfactory apparatus was totally 
destroyed was verified by autopsy dissections made after the close of the observations. 
OTHER FISHES. 
The sea-robin (Prionotus carolinus) . — The three finger-like rays of the pectoral 
fins of the gurnards have long attracted the attention of zoologists, and the American 
species of Prionotus have been made the subject of a careful research by Morrill 
(’95). He finds that, as in the closely related European Triglct , the free ray r s are 
totally devoid of terminal buds or other specialized sense organs and that the sensory 
nerves with which these free rays are so abundantly supplied end free, like tactile 
nerves in general. 
lie also made some interesting physiological experiments. The normal food of 
these species, so far as known, is small fish, young clams, shrimps, amphipods and 
other small Crustacea, squid, lamellibranch mollusks, annelids, and seaweeds. (Linton, 
1901, p. 470.) They are constantly feeling about the sand, turning over stones and 
feeling under them, etc., with these free rays, and undoubtedly find their food largely 
in this way, especially the annelids, mollusks, and Crustacea; but in captivity the 
eyes are used chiefly in securing the food. Morrill writes further: 
In order to test the use of the free rays independently of sight the crystalline lens and cornea 
were removed from some fish, and in other cases the cornea was covered with varnish, balsam, or tar. 
The repeated experiments were negative in their result, as the fish paid no attention to the food, even 
when it was placed in contact with the free rays. 
Morrill concludes “that the free rays have been modified for tactile purposes, 
and that they are mainly, if not altogether, used in searching for food.” 
Morrill’s dissections leave it uncertain whether the free rays of the pectoral fins 
receive communis nerves, as they should do, of course, if these organs had given 
evidence of gustatory powers. The only source of communis fibers for this fin 
would be through the ramus lateralis accessorius (r. recurrens facialis). Stannius 
(1849, p. 49) did not find this nerve in Trigla gumardus and T. hirundo. I dissected 
a specimen of Prionotus carolinus and found the same to be true here, so that it can 
be taken as assured that no communis nerves reach the pectoral fin in this species. 
After an examination of the feeding habits of the adult sea- robin and of young 
specimens about 10 cm. long 1 quite agree with Morrill that the reaction to food 
particles by the free fin rays is tactile only, with no gustatory element. When 
adults are fed with fresh clams or mussels, the shells split open to expose the meat, 
they turn and bite out the meat as soon as a free ray touches the soft flesh. Young 
fishes did not give this reaction so invariably, and evidently relied much more on 
sight. Clean clam shells filled with melted gelatin were reacted to like the fresh 
clams once or twice by each fish, but. usually were thereafter ignored. 
The free rays constantly stir up the sand and gravel of the bottom. If soft 
edible particles are touched the head may be turned to snap them up, especially with 
old fishes.. With younger ones this usually does not happen unless the particle is seen 
