The Montgomery advertiser., 1903-04-09
SCIENTIST SAYS FISH HEAR
Elaborate Series of Experiments by a Harvard Professor Proves That at Least Some Species Can
 Recognize Sounds by
 Means of Auditory

When Isaak Walton decided ito advise
 anglers to be patient and forbear swear | ing, lest they be heard and catch no fish," he gave his approval to gener- | ally accepted theory of hearing in fishes. l True, this notion that fish can hear has | been denied of late years by several mod
 ern scientific observers. but now comes
 Prof. c. H. Parker of Harvard Univer- l sity with 6 series of experiments recent
 ly performed at the Biological Labora- | sion at Woods Hole, to substantiate, at least fin part, the fishermans time-hon- l ored supposition. That all fishes have power of hearing Professor Parker does
 not assert. But none the less he declares
 that he is fully convinced that the par | ticular kind of fish used in his recent l investigation do hear sounds.
 l This conclusion seems, at first glance, quite opposite to the one reached by the Viennese physiologist. kreidl, who de- | cided, some years ago, that the ears or a goldfish have no value whatsoever as
 hearing apparatus and that the goldfish | feels it. Yet the two conclusions may not be so irreconcillable. It does not fol- low, for instance, because the little New | England minnow, or "killfsh." on which ments, did hear. that the goldfish used in | the European experiment may not have
 been quite incapable of heaSng. Indeed;
 Upsala, Sweden, who has just finished | a somewhat similar series of experiments | with the sense organs Of fishes. teis us | that a tish's actual hearing Is matter l not yet finally proved either one way or | the other.
 l 1t was known as long ago as the be- | ginning of the seventeenth century that | fishes had what appeared to be ears. and | because they had ears the earlier scient- ists naturally concluded they could hear. Not until late in the nineteenth century did 1t occur to anybody to advance the belief that fish live in perpetual silence.
 literally feeling sounds. not hearing them. Kreidl for instance, found that a gold fish whose hAaring apparatus had been altogether removed responded to sound just like a normal goldfish; and Bateson, the English zoologist discovered that a number of different kinds of fishes, evil dently affected by the sound of severe
 shocks or concussions-such. for example. as the blasting of rocks or violent blow of a stick on the wall of an aquarium
 were apparently deaf to minor noises.
 Kreidl, indeed, demolished very pretty
 tradition. The trout in basin at the Benedictne monastery in Krems, Austria,
 were popularly supposed to assemble for food on hearing bell. But unfortun- ately the Viennese scientist discovered on investigation that the trout assembled Just as promptly, bell or no bell, on catching sight of a man standing on the
 bank of the basin. and that no amount Of bell ringing would make them assem- ble unless the man was visible.
 Naturally, however. one might argue, if the ears of a certain Ash do not serve 1t to hear with. they must have some other equally important ofice, and 1t has become clear, through the independent investigations of several scientists dur ing the last two decades that they do play an important part fin maintaining the balance of the fish as 1t swims through the water. Professor Lee of Columbia University. in studying the ac- ton of several species of fish when sub jected to sounds that the sole function of their ears, 20 called, was to keep their bodies in equilibrium.
 Professor Parker, however. does not al- together agree with these other scient- fists. He starts from the we'll known fact that certain fish, like the sea robin, make sounds when attacked-the natural infer ence being that the sound Is heard by both creatures. In a series of experi- ments conducted last summer he went on to show that at least one species of fish -the small green killfish before mention ed-has ears that are distinctly service able to hear with
 The apparatus which Professor Parker used in his experiments consisted of a deal sounding board on which a bass yioI string was so stretched that It's vibra- tions could be transmitted through the board to the watetr. Its sounds were thus practically made under water. The string itself was kept tuned to about forty vi- brations second tone among the lowest ever used in music and of about the same pitch as the sounds uttered by the few known fishes that have voices Within the aquarium was hung a small cage. one end of which. parallel with the sounding board, was covered with net ting to permit free entrance to any sound 1 from without. This cage was suspended from supports independent of the aqua rum itself, so that no oscillation of the l aquarium framework would be communi- | cated to the cage and in it were placed, | one by one. the klllif1sh utilized in Pro | lessor Parker's experiments To sum up | apparatus provided that the sounds to | which the Imprisoned fish was to be sub | Jected should be well sustained and of | relatively low intensity rather than of the | kind to produce a concussion or shock | that should be felt" instead of heard" |
 Three classes of kllifish were tested first those that were entirely normal: | second, those In which the nerves of the | ears had been cut and which were there | fore unquestionably deaf, even if thev | had originally been able to hear; and, | been rendered insensitive and which ac- cording could not serve as medium for | noting any phenomena incident to the | sound of the viol string.
 As soon as the normal fish was placed | in the cage and the bass viol string set in vibration, four different reactions" to use the technical expression were imme- diately noticeable. The rate of the gill | movements increased for. brief pericd. The pectoral fins, if quiet. were set in motion. The tail fins often vibrated. Finally, the whole fish sometimes gave a spring. just as if startled by an unex- pected sound. Ten normal fishes were subjected to ten tests apiece. and in nine ty-six cases-just 96 per cent of all-the movement of the pectoral fins, which were chosen as the reaction most satisfactory for observation. responded to the sound | nroduced the instrument.
 Ten fishes whose ear nerves had been | onerated on at least twenty-four hours | before the experiment were tested in a similar fashion; but in 100 trials therel