6 Can Science Explain Life? 



sharp line of demarcation between living and non- 

 living things. Although growth and reproduc- 

 tion, in their broadest aspect, amount to nothing 

 more than self-duplication, yet they are funda- 

 mentally different from any of the other processes 

 heretofore known to science. 



Biological growth does not proceed in the same 

 manner as the growth of crystals because exten- 

 sive chemical transformations take place during 

 the process of metabolism whereas the growth of 

 crystals involves no permanent chemical change 

 whatever. It also differs from crystal growth in 

 that the assimilation of food by the cells of living 

 organisms does not require saturated solutions 

 such as are necessary for the growth of crystals. 

 Another difference is in the final result produced, 

 for although biological growth can produce or- 

 ganisms of the utmost complexity and variability 

 and generally of rounded contour, yet crystal 

 growth produces only such structures as are of 

 angular contour, internally homogeneous, and 

 neither complex nor variable. 



Biological reproduction, or more specifically 

 cell division, involves more than mere dispersion 

 or subdivision because the progeny retain, either 

 actually or potentially, not only the chemical com- 

 position but also the specific physical organization 

 of the parent cell. Neither can cell division be 



