WHAT IS LIFE? 59 



tation of their two orifices. We may therefore conceive Life 

 without Motion, cand Motion without Life ; and thus, with 

 some plausibility, ask whether the movements exhibited by 

 the tentacles of the Terehella and Medusa ought to be 

 received as indications of life ? Here I get myself into a 

 fix. The thought arises that what I observe in these ten- 

 tacles is owing to a surplus residue of vitality, retained by 

 them, not to any central source of self-renewing vitality, 

 such as the organism possesses ; consequently, inasmuch 

 as these tentacles neither grow, nor reproduce them- 

 selves, they fail to fulfil the primary conditions of Life ; in 

 other words, they are not alive, in spite of movements, 

 apparently spontaneous, during a whole week of indepen- 

 dent existence. 



In arguing with oneself, one has always a respectful anta- 

 gonist, to whose objections every attention is given. Hav- 

 ing given due attention to myself, I now turn round upon 

 myself, and remark with some emphasis : Very true ; but 

 you overlook the important fact that in speaking of Life as 

 the triple unity of Nutrition, Keproduction, and Decay, you 

 are speaking of the whole organism ; whereas in the ten- 

 tacles of Terehella and Medusa, we were considering an 

 organ, not an organism ; and to apply your definition to an 

 organ, would be to deny its vitality altogether. The animal 

 cannot be considered as wanting in either of the tri[)le 

 terms ; but the very essence of an organ is that it special- 

 ises a function — that is to say, takes upon itself to do some- 

 thing for the benefit of the whole animal, in return for 

 which it is absolved from doing many things which the 



