"fHE COMING OF LIFE 5 



semifluid substance about as viscid as mucilage or cold 

 molasses. It is not surrounded by any rigid cell-membrane 

 and can put out rootlike or rounded projections, pseudopodia. 

 It can withdraw these or can " flow " into one of them and 

 thus move. The secret of this power of contractility, how a 

 little mass of semifluid substance can continually change the 

 tension of different portions and '' squeeze " itself into new 

 forms, is still an exceedingly difficult question. 



It distinguishes its food before it comes in contact with it 

 and hence seems to possess the sense of smell. It possesses 

 a power which we must call consciousness. It responds to a 

 variety of stimuli, in certain situations it seems to experiment 

 by a sort of '' trial and error " and to '' feel its way." 



The engulfed particle of food, alga or bacterium, is sur- 

 rounded by a droplet or vacuole of acid fluid and is dis- 

 solved, digested; whatever is insoluble goes to the surface 

 and is discharged. The dissolved nutriment is either burned 

 up to furnish energy or stored up in granules, '^ oil-globules," 

 or other forms; some of it passes into the nucleus and is here 

 changed to cytoplasm or nuclear substance; here, and also in 

 the cytoplasm, " dead matter " is changed into living sub- 

 stance, the constantly recurring miracle of life. The products 

 of combustion and the waste substances of the body are dis- 

 charged or excreted at the surface of the cell. Here also 

 oxygen is absorbed, and respiration takes place. The amoeba 

 is a vortex or whirlpool on the face of nature continually 

 taking in, building up materials, using them in a great variety 

 of ways, oxidizing or disintegrating them again and cast- 

 ing them out. But it is a very enduring permanent whirl- 

 pool outlasting the everlasting hills. 



The amoeba grows. When it has reached a certain size, 

 it divides into two new and young amoebae, and there is no 

 old amoeba left to die. It seems to elude and outwit death 

 and to be potentially immortal, especially if the nucleus is 

 rejuvenated — as is usually the case among the protozoa — 

 by an act of fusion or conjugation of two individuals, the 

 promise of sex. 



