216 G. H. PARKER 



observer may be given to every actinian there and thus induce 

 expansion in what seems to be an anticipatory manner, whereas 

 in reaUty it is a response to a direct stimulus. It is in some such 

 way as this that in my opinion Pieron has probably been de- 

 ceived, for from my own observations I am led to concur with 

 Bohn ('08 a) in questioning the existence of reactions really 

 anticipatory. Such rhythms as have thus far been studied in 

 sea-anemones seem, therefore, to depend upon immediate rhyth- 

 mic stimuli external in origin as the changes of the tides or the 

 change from day to night and the reverse, and not upon rhythmic 

 operations of a more internal nature such as probably control the 

 pulsing of a jellyfish or the beat of the vertebrate heart. 



4. PSYCHOLOGY 



The term psychology as applied to such lowly animals as 

 actinians is commonly used to cover a discussion of those activi- 

 ties which may or may not give grounds for the assumption of 

 primitive psychic conditions in these forms. In this non-com- 

 mital sense it is used here as it already has been used by many 

 who have held most divergent views as to the problems involved. 

 In all instances it implies a fundamental consideration of the 

 more complex nervous processes of a given group of animals; a 

 standpoint which it is quite appropriate to assume concerning 

 the actinians. When we examine the organization of the human 

 body and note the perfection of its voluntary adj ustments with 

 their involved psychoses and the equal perfection of such neuro- 

 muscular but non-psychic activities as those exhibited by the 

 heart, we may reasonably ask. Is the actinian an organism that 

 responds as the vertebrate heart does, or does it necessarily in- 

 clude in its activities elements of a psychic order? It is with 

 questions such as these that the psychology of the actinians is 

 concerned. 



As Baglioni ('13) has pointed out, the neuromuscular reac- 

 tions of actinians fall into two general classes, first, responses 

 to beneficial stimuli, and, secondly, responses to noxious influ- 

 ences. These two categories doubtless represent the neural 

 background on which rest those states of so-called pleasure and 



