Heat and Light on Polypes. 8 1 



It may feem extraordinary to talk of any 

 Creature's being afFe6led by Light, in whom 

 no Eyes are to be found, and yet this Ani- 

 mal plainly appears to be io ; for after ftand- 

 ing a (hort Time in the dark, it is ufually 

 found contracted and without Motion : and 

 when brought out of a dark Place into the 

 Light, it fcarce ever fails to extend its Body 

 and Arms, and play them about briilcly. 



When firft I obferved this, I apprehend- 

 ed, that as my Glafies were fl^iut up in a 

 clofe Book-Cafe, the Change of Air and not 

 of Light might be the Occafion of it, and 

 therefore put a Number of them in an open 

 Veffel, on the Top of a Cabinet; where 

 (though they were not wholly in the dark) 

 I found them moft commonly contradled: 

 and when I brouo;ht them to a better Lieht 

 they conftantly ftretched themfelves out. I 

 might add, that when they approach a Candle 

 they always do the fame; but, perhaps, it 

 will be thence fuggefted, that Heat may be 

 fuppofed to affect them rather than Light. 



I fhall not at all Difpute whether of the 

 two it is : but be it one or the other, it 

 feemsan undeniable Evidence, that this Crea- 

 ture is pofTefled of a moft exquifite Senfe of 

 Feeling. 



However, Mr. Trembley has made an 

 Experiment with the little green Polvpes, 

 which appears to be conclufive. He fitted 

 a cj^lindrical Glafs, wherein he kept a Num- 



G ber 



