564 



THE PLANT'S PLACE IN NATURE 



What is the utmost that may be inferred from such experiments? 

 Have lifeless things really been made to act as if they were alive? 

 It is plain that all we have here are simply imitations of isolated 

 vital processes, and not such a coordination of activities as character- 

 izes a living being. Living protoplasm does not merely feed, or grow, 

 or reproduce, or respond to stimuli : it does all these things at once, 

 and more; and its activities are so coordinated as to accomplish 

 definite ends. Nothing which can do all that protoplasm does 

 has ever been manufactured. Supposing it were possible, however, 

 to effect a combination of elements which would imitate aU the 

 phj^sical and chemical activities of protoplasm, and all at once; 

 what would that mean? We could be sure that such artificial 

 protoplasts would alwa5's do the same thing under the same condi- 

 tions, and that corresponding parts would always act exactly alike. 



Acetyl chloride Zinc ethyl Methylethylketone Zinc chloride 



CH, 



CH, 



1 

 COCl 



COCl 



I 



CHa 



Zn 



CH., 



I 

 CHs 



'CH:> 

 CH:j 



I 



CH. 



I 



CO 



I 

 CH3 



CH3 



I 

 CO 



+ Zn CI, 



CH 



CHa 



Methylethylketone Oxygen Acetic acid 



CH3 CH;, 



CH.. 



1 

 CO 



I 

 CH, 



+ 



30 



COOH 



CH,, 



I 

 COOH 



CH, 



I 

 CH2 



I 

 CO 



I 



CH, 



30 



CH, 



I 

 COOH 



CH, 



I 

 COOH 



Thus for every two molecules of acetic acid four arc finally produced. 



