BULLETIN OF THE UNITED STATES FISH COMMISSION. 
266 
or tactile. The fleshy, cutaneous appendages of the skin were especially tested to 
bring out possible gustatory reactions, but with negative results save for those bor- 
dering on the lips, where it was impossible to exclude the participation of taste buds 
on the lips. This agrees with the anatomical findings of Miss Clapp (1899), whose 
careful study of the skin of this fish failed to reveal any terminal buds on these 
appendages or elsewhere away from the buccal cavity . A jet of sea water directed 
against these appendages or the body surface in general usually disturbs or frightens 
the animal merely, if it is noticed at all. A jet of clam juice similarly applied calls 
for the same reaction unless it is so directed as to reach the lips, in which case the fish 
reacts to it just as the hake and tomcod do, attempting to take the tip of the pipette in 
the mouth. The following solutions were applied in the same way by a tine pipette 
to various parts of the body surface: 0.2 per cent hydrochloric and 1 per cent hydro- 
chloric acid in sea water, and 0.1 per cent quinine sulphate in sea water. In all cases 
the fishes paid no attention to the stimulus unless the substance was so applied as to 
come into contact with the lips. The experiments lead me to conclude that the toad- 
fish can taste only within the mouth and on the lips, and that if the cutaneous appen- 
dages have any sensory function it is tactile only. 
CONCLUSION. 
The morphological and physiological significance of the terminal buds of fishes 
is a problem which has exercised some of the ablest morphologists for over half a 
century. The methods of the older anatomy have signally failed to yield concordant 
results. Not until the innervation of the cutaneous sense organs was worked out 
from the standpoint of nerve components was this confusion relieved. The older 
morphologists (Schulze, Merkel, and others) discovered a morphological criterion, 
the “hair cells,” by which the terminal buds could be distinguished from cutaneous 
sense organs belonging to the lateral-line system. But this fact attained its signifi- 
cance only when it was discovered that the organs of the lateral-line system, or neu- 
romasts, which possess the “hair cells,” are always innervated by lateralis nerves 
related centrally to the tuberculum acusticum, while terminal buds, which lack the 
“ hair cells,” are always innervated by communis nerves which are related centrally 
to the primary gustatory centers of the vagal and facial lobes. 
Presumably, then, lateral-line organs and terminal buds have different functions; 
and, further, the function is probably not tactile in either case, since all parts of the 
skin receive general cutaneous nerves in addition to the special sensory components, 
and these general cutaneous nerves are related proximallv to different centers from 
either of the others. The lateral-line organs are known to lie used in the maintenance 
of bodily equilibrium and the perception of mass motion of the water. (Compare 
the recent works of Lee and Parker.) On the other hand, the terminal buds are 
related in structure and innervation to undoubted taste buds of the mouth, and hence 
the inference that their function is taste. This inference is abundantly confirmed by 
the experiments here recorded, and the function and morphological rank of the 
terminal buds are at last definitely fixed. 
It may be regarded as established that fishes which possess terminal buds in the 
outer skin taste by means of these organs and habitually find their food by their 
