7<D The Animal Mind 



seized and then dropped. If the paper ball be soaked in fish 

 juice, on the other hand, it is seized as eagerly as the fish 

 meat. A negative reaction, consisting in the withdrawal of 

 the tentacles affected, may be produced by applying a bit 

 of paper soaked in quinine solution or by the discharge of qui- 

 nine solution from a pipette near the tentacles (237, 288). A 

 peculiar form of negative reaction has been observed in Adam- 

 sia, and more strikingly in Cerianthus, when a paper ball soaked 

 in fish juice has been passed from tentacle to tentacle till it 

 has nearly reached the mouth. The process is suddenly re- 

 versed, and the ball is passed back from one tentacle to another 

 till it reaches the outside edge and is dropped off. Nagel, 

 the observer, thinks the stimulus for this change of reaction 

 is the gradual wearing off of the "sapid parts" of the ball 

 during its passage toward the mouth it might be the 

 squeezing out of the meat juice and calls special atten- 

 tion to the fact that the reaction whereby the paper is got rid 

 of is wholly different from the ordinary reaction of a tentacle 

 to mechanical stimulation, which, as we have seen, does not 

 involve seizing the object at all. A tentacle touched by a bit 

 of moistened filter paper ordinarily responds, if at all, by a 

 mere contraction without the winding seizure of the object. 

 Touched by the same object "handed on" to it by a tentacle 

 nearer the mouth than itself, it seizes the paper and passes it 

 on to the tentacle beyond it. The cause of this difference in 

 behavior seems to lie in the processes that have been taking 

 place just previously. Nagel does not hesitate to say that a 

 psychic process must be involved, but its details are not easy 

 to construct (291). 



Another sea-anemone, Aiptasia, has but one ring of ten- 

 tacles, and like Tubularia crocea, instead of showing different 

 responses to contact stimulation alone and to contact plus food 

 stimulation, it merely reacts with greater emphasis to the 



