THE PHENOMENA OF LIFE 157 



up, and then suddenly fall again for several millimetres. We 

 have frequently watched this rhythmic movement for an hour 

 or more — a slow gradual elevation of the extremity of the 

 twig and a rapid fall recurring every four seconds or so. 



It may be objected that the substance of an osmotic 

 growth is continually undergoing change, whereas a living 

 organism transforms into its own substance the extraneous 

 matter which it borrows from its environment. The distinction, 

 however, is only an apparent one. The substance of a living 

 being is also continually undergoing chemical change; it does 

 not remain the same for a single instant. We see an evidence 

 of this change in the evolution of age ; the substance of the 

 adult is not that of the infant. In some living organisms 

 such as insects, especially the ephemeridae who have but a 

 brief existence, this change of substance is even more rapid 

 than that in an osmotic growth. 



It has been objected that osmotic productions cannot be 

 compared with living organisms since they contain no 

 albuminoid matter. This is to consider life as a substance, 

 and to confound the synthesis of life with that of albumin. 

 If albumin is ever produced by synthesis in the laboratory it 

 will probably be dead albumin. All living organisms contain 

 albumin ; this is probably due to the fact that albuminoid 

 matter is particularly adapted for the formation of osmotic 

 membranes. Our osmotic productions are composed of the 

 same elements as those which constitute living beings; an 

 osmotic growth obtained by sowing calcium nitrate in a solution 

 of potassium carbonate with sodium phosphate and sulphate 

 contains all the principal elements of a living organism, viz. 

 carbon, oxvgen, hydrogen, nitrogen, sulphur, and phosphorus. 

 The whole of the vegetable world is produced by the osmotic 

 growth of mineral substances, if we except the small amount of 

 oreanic matter contained in the seeds. 



The most important problem of synthetic biology is not so 

 much the synthesis of the albuminoids as the reduction of 

 carbonic acid. In nature this reduction is accomplished by the 

 radiant energy of the sun, by the agency of the catalytic 

 action of chlorophyll. 



