THE ORGAN AND SENSE OF TASTE IN FISHES. 
259 
have, however, to investigate the parts played by tactile, gustatory, and olfactory 
sensations. 
Bateson’s remarks (’90, a , p. 214) in this connection on the rockling may be 
quoted here. The three-bearded and the live-bearded rockling are nocturnal and lie 
still all day. 
Generally, both the animals take no notice of food until it has lain in the water some minutes, 
when they start off in search of it. The rockling searches by setting its filamentous pelvic fins at 
right angles to the body-, and then swimming about feeling with them. If the fins touch a piece of 
fish of other soft body, the rockling turns its head round and snaps it up with great quickness. It 
will even turn round and examine uneatable substances, as glass, etc., which come in contact with its 
fins, and which presumably seem to it to require an explanation. The rocklings have great powers 
of scent, and will set off in search of meat hidden in a bottle sunk in the water. Moreover, a blind 
rockling will hunt for its food and find it as easily as an uninjured one. 
The above, taken in connection with other passages, shows that this author con- 
siders that the food is found largely by scent, and that the fin reaction is essentially 
tactile, though he has seen the sense organs on the pelvic fins and recognized their 
resemblance to taste buds. 
Examination of stomach contents shows that the normal food of these hake is 
largely crustaceans, particularly shrimps. I fitted up a tank with some seaweed and 
put into it a large number of prawns ( Palxmonetes ), mostly living, but some dead. 
Upon putting the hake into this tank, they immediately ate some of the dead prawns 
from the bottom and afterwards caught the live ones, but very slowly and with many 
failures. The response seems to be wholly visual. The fishes would repeatedly 
pass directly over living prawns, touching them with the fins or being brushed by 
their antennae, but so long as the crustaceans were quiet they seemed not to notice 
them. If, however, a prawn was killed and crushed and thrown back into the water, 
it was immediately found. Upon another occasion I put a live clam into the tank 
with the hake, where it remained for several days, with siphons greatly extended. 
The fishes repeatedly brushed over this siphon with their free fins, but never paid 
any attention to it, though if a similar siphon were cut off from a live clam, so 
as to allow some of the juices to escape, it would be immediately taken and eaten. 
Evidently live food is not clearly located by the gustatory organs of the fins. 
Besides observing as fully as possible the normal feeding habits of the hake, I 
experimented upon the reactions to stimuli applied to both the pelvic and the 
filamentous dorsal fins. As mentioned by Bateson, the pelvic fins are freely used to 
explore all manner of substances which may attract the notice of the fish, whether 
edible or not. After these fishes have become accustomed to being fed small bits 
of meat or clam or mussel {Modiola) in their tank, they immediately swim toward any 
small unfamiliar body with the pelvic fins thrust forward to touch it before the 
mouth reaches it. Sometimes the tips of these fins close over it with a movement 
strongly suggestive of grasping, though of course this they can not do. 
Upon testing by contact with meat or other bait, the free dorsal filament is 
found to be quite as sensitive to gustatory stimuli as the filamentous ventrals. The 
reflex in this case is very characteristic and constant — the fish upon touching a 
savory morsel checks its forward movement and immediately ‘‘ backs water” so as to 
reverse the movement of the body until the object is directly above the mouth, when 
