CONTRIBUTIONS FROM THE ZOOLOGICAL LABORATORY OF THE MUSEUM OF COMPARATIVE ZOOLOGY AT 



HARVARD COLLEGE. NO. 290. 



ACTINIAN BEHAVIOR 



G. H. PARKER 

 1. INTRODUCTION 



The beha\dor of actinians has been interpreted in the past 

 in many different ways and the subject even now is open to the 

 greatest uncertainty. Gosse ('60, p. 81), one of the most enthu- 

 siastic and industrious students of these animals, after watching 

 the creeping of Sagartia pallida, wrote that '^it was impossible 

 to witness the methodical regularity of the process, and the fit- 

 ness of the mode for attaining the end, without being assured 

 of the existence of both consciousness and will in this low ani- 

 mal form," But such naturalists as Gosse had been schooled 

 to regard adaptations as necessary evidence of intelligence and 

 it was only gi'adually that these workers were brought to see 

 in Darwin's natural selection one means at least of explaining 

 adaptations without recourse to such a factor. So far has this 

 mechanistic movement gone in the explanation of animal reac- 

 tions and so vigorously have such workers as Loeb ('99) applied 

 its principles that Baglioni ('13) in his general account of the 

 activities of actinians felt called upon to argue at length for the 

 presence even of nervous action in these forms. It is not my 

 purpose to discuss the question of 'consciousness and will' of 

 the existence of which in these lowly creatures Gosse was so 

 firmly convinced. The futility of such a procedure is too evi- 

 dent. But it is planned to examine some of the more complex 

 activities of these forms with the view of gaining a clearer insight 

 into their elements and into the relation of these elements to 

 the animal as a whole. 



The activities of almost every species of organism are directed 

 now into one, now into another of three principal channels; these 

 are, first, the great array of protective measures against unfa- 



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THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 22, NO. 2 

 FEBRUARY, 1917 



