The Origin of Life 15 



understand the specific difference between non-living 

 and living matter. It is true that a crystal can grow, 

 but it will do so only in a supersaturated solution of 

 its own substance. Just the reverse is true for living 

 organisms. In order to make bacteria or the cells of 

 our body grow, solutions of the split products of the 

 substances composing them and not the substances 

 themselves must be available to the cells ; second, these 

 solutions must not be supersaturated, on the contrary, 

 they must be dilute; and third, growth leads in living 

 organisms to cell division as soon as the mass of the 

 cell reaches a certain limit. This process of cell divi- 

 sion cannot be claimed even metaphorically to exist in 

 a crystal. A correct appreciation of these facts will 

 give us an insight into the specific difference between 

 non-living and living matter. The formation of living 

 matter consists in the synthesis of the proteins, nucleins, 

 fats, and carbohydrates of the cells, from the spHt pro- 

 ducts. To give an historical example, Pasteur showed 

 that yeast cells and other fungi could be raised on the 

 following sterihzed solution : water, 100 gm., crystallized 

 sugar, 10 gm., ammonium tartrate, 0.2 gm. to 0.5 gm., 

 and fused ash from yeast, o.i gm.' He undertook this 

 experiment to disprove the idea that protein or organic 

 matter in a state of decomposition was needed for the 

 origin of new organisms as the defenders of the idea 

 of spontaneous generation had maintained. 



* Pasteur, L., Annal. d. Chim. et d. Physique, 1862, 3 s6t., Ixiv., i. 



