Persistence of E.vperiineiital IVarning-Color Reaction. 295 



natural, positive response of the snappers toward it was inhibited. 

 This positive response, in so far as it involves the taking of small, 

 near, possible- food objects, is doubtless instinctive: in so far as it in- 

 volves taking the specific food atherina it is habitual. Had the food 

 offered been such that the snappers had had no previous experience of 

 it, their positive response would have been instinctive only. To in- 

 hibit such a general instinctive response requires, as shown elsewhere 

 in this paper (p. 307), a much smaller number of experiences than are 

 necessary to inhibit a response that has become habitual. That an 

 habitual response, toward a particular food commonly present in the 

 environment should be as readily inhibited as in experiment 32 was 

 unexpected and shows a high degree of modifiability in the behavior 

 of the snappers. 



VII. THE RETENTION OF THE RED-UNPALATABILITY WARNING 

 ASSOCIATION IN THE GRAY SNAPPERS (ME.WORY). 



The color red had come to have a warning significance for the gray snap- 

 pers as a result of their experience with unpalatable red atherinas an ex- 

 perience which closed on July 19, 1907. This colony was not afterwards 

 offered red atherinas, except at the time indicated below and for the purpose 

 of testing the retention of the red-unpalatability association. On July 23 

 the colony was fed from 200 to 300 formalin atherinas, newly rinsed in sea- 

 water to remove the formalin. These were taken, but many of them were 

 afterwards ejected and lay on the bottom unnoticed. On July 24 an attempt 

 was made to feed these snappers on formalin blue atherinas, but after tak- 

 ing 30 or 40 they began to eject them and would then take no more. On 

 July 26 the colony took 21 out of 30 blue and yellow formalin atherinas 

 offered them. 



On July 27, 8 days after the red warning association had been estab- 

 lished, I tried all the morning to get the snappers of this colony to take 

 formalin red atherinas (untentacled). They took a few very slowly and 

 then stopped. They took formalin normals more readily and also took blue, 

 but if red was offered immediately after blue or white, it was, even then, 

 taken very slowly. Apparently the snappers still retained the red unpala- 

 tability association. The red used was a cardinal red much purer than the 

 red used in the association experiments. 



On August 8, 20 days after the close of the association experiment with 

 formalin tentacled red atherinas, the last attempt was made to feed the labor- 

 atory colony on red fish. All the red and blue and yellow atherinas used 

 had been removed from formalin, washed and stained some 10 days before, 

 and had since laid in a moist atmosphere, so that the last trace of formalin 

 had probably evaporated from them. Formalin blue atherinas were first 

 thrown and 4 or 5 of these were taken very carefully. Red was then 

 thrown. Some of both blue and red sank, others floated. Tlie reds re- 

 mained entirely untouched, even while they sank among the snappers and 



