BEHAVIOR OF SEA-ANEMONES. 275 



result that such specimens as found sand proceeded to cover 

 themselves as far as possible. In the light of current activity 

 and interest in the matter of behavior it occurred to me to sub- 

 ject these creatures to a few experiments with a view of testing 

 their reaction to light, and perhaps a few other environmental 

 factors. 



An examination of the available literature has brought to light 

 but few instances in which any observations have been made 

 concerning the behavior of actinians in relation to light. The 

 Hertwig brothers, '79 (" Die Actinien Anatomisch und Histo- 

 logisch," p. 191), cite brief observations made by Quatrefages 

 on species of Edivardsia in 1842, and by Haime on Cerianthus 

 in 1854, and include likewise brief references to their own obser- 

 vations on a deep sea-anemone, Cladactis costce, in the Naples 

 aquarium. 



Quatrefages found that when a ray of light from a lamp 

 was condensed upon the specimens by means of a lens they 

 partially retracted. Haime observed that in bright sunlight 

 species of Cerianthus contracted within their tubes and later ex- 

 panded when the light became less intense. The Hertwigs record 

 simply the fact the specimens during full daylight were more or 

 less contracted and expanded as the light became less intense. 

 " Im tageslicht zieht sie ihren Korper stark zusammen und erst 

 wenn es zu dunkeln beginnt, dehnt sie sich auf das Vier- bis 

 Funffache aus und entfaltet ihre Tentakeln, di zuvor eingezogen 



waren.' 



Jourdan has recorded a similar observation (" Les Sens chez 

 Les Animaux Inferieurs," Paris, 1889), made upon a species of 

 Paractis in which similar behavior was exhibited. " J'ai pu voir 

 moi-meme, sur des Actinies du genre Paractis, des manifestions 

 evidentes de cette sensibilite speciale. Des Orties de mer restent 

 fermees aussi longtemps qu'on les expose a une lumiere trop vive ; 

 alles ne o'epanouissent que lorsqu'on les met a 1'abri des rayons 

 lumineux " (p. 221). 



Eloactis producta. My first observations were made to con- 

 firm those already cited, namely, to clearly demonstrate their 

 nocturnal habit. Placed in the aquaria of the general labora- 

 tory, and in a few cases in smaller jars in my private laboratory, 



