The daily morning journal and courier., 1907-01-11
MEMORY OF FISHES.
Investigation Into the Beginnings of
 the Mind.

the Mind.
 The Carnegie Institution Laboratory at the Tortugas consists of seven buildings upon Loggerhead Key, and it designed to afford the best possible fa- cilities for the study of the life of the Gulf Stream and the coral reefs. The laboratory is provided with a seagoing yacht and three good launches for vis- iting the neighboring reefs and for cruises over the Gulf Stream. The yacht is 60 feet long, and can remain at sea for weeks at time, being pro vided with powerful engine and sails.
 Researches have been conducted during the last two summers, too short a time since the opening of the labora- ] tory to permit me to speak personally of the investigators or in detail of their results, especially as many of | the researches ore of an elaborate na- ture and are not yet completed for publication. The following brief state ment will, however, give fair idea of some of the best established results | achieved by investigators working at the laboratory.
 One investigator studied the habits pf the reef fishes, and found that the { irlost abundant predatory fish of the { Tortugas reefs was the gray snapper, which commonly feeds upon a little l silvery sardine. If some of these sar- dires be dyed bright red and then sthrown into the sea, together with some normal sllvery sardines, the sil- livery ones are at grst eaten more read lily than the red, but the gray snap pers soon learn that bright red sar- dimes are good to eat, and will then devour them as eagerly as if they were normal in color. The investigator i then dyed some sardines bright blue and threw them In together with red i and silyery ones. At first the blue were relatively avoided, but soon the EIdN SlldpJGl0 lIldl tlAVJ lOO i were palatable. Small portions ofjel- lNf1shes were now attached to the blue l sardines,and the gray snappers siez- ed them greedily, but were stung by the pieces of jellyfish. In a few min utes they learned to avoid the blue, but still ate red and silvery sardines. The next day, however, the gray snappers had forgotten this experience and the patient investigator was oblig- ed to teach them anew
 l Another investigator demonstrated that even such lowly creatures as sea anemones and corals pursue the meth cd of trial and error in their behavior, and that they recognize things in1u- rious and avoid them. Moreover they at first avoid each sort of inju- rious stimulus in a fixed and constant way, but if this fails they adopt new methods.
 The associative memory of caterpil. lars may endure agout half minute but they cannot retain the memory ot an experience for solonga time as a minute and half. Results such as the above fay appear trivial to the lay reader, but their import increases when we consider that in these simple forms we are dealing with the begin. nings l2f mind.
 One of the most distinguished zoolo' gists working at the Tortugas found that the substance of the eggs of leu uyfish is differentiated into three con centric layers, one of which forms the outer skin, one the muscular or sup porting mechanism and one the diges tive system. Previously he had dis t covered that the eggs of higher ami mals were organized in the same man ner. He thus striklngly demonstrated the intimacy of relationship whicl pertains between the highest and th lowest of animals. The difference be tween jellyfish and a vertegrate il mainly one of degree, not of kind.
 Another investigator has carried ou very carefully planned series of ob servations upon regeneration whicl show that the animal with the greate number of removed parts regenerate each and every part more rapidly thai the animal with the lesser number o removed parts.
 Studies upon mullusks, tunicates fishes, fish parasites and protozoa ar being pursued, and series of elab crate observations will soon be pub lished upon the reactions of crabs an starfishes, and upon the developmen of jellyfshes discovered at Tortugas.
 One student finds that the pulsatiol of iellyfishes and of the hearts of va rious animals is strongly stimulated b. the sodium potassium and calcium chlorides of the sea water, or of tn fluids permeating the heart; but mag nesium inhabits this stimulus, thu causing the pulsating organs to b be merely upon the threshold of stim ulation and allowing slight interna stimuli to produce rythmical contrac tfons. Organs can pulsate only whel stimulus is counterbalanced by al inhibitor, thus allowing one or the oth A.-1-