Heredity and Education. 327 



atoms in the molecule and in part to the kinds and numbers of 

 atoms. In a similar way the molecules in crystals of various 

 minerals are held to have a geometrical arrangement peculiar 

 to each mineral. This geometrical form is never varied ex- 

 cept in accordance with well-known laws, and the mineral can 

 be recognized in all cases by the form of the crystal. The 

 crystallographer has demonstrated that crystals grow by addi- 

 tions to their exterior surfaces, and naturally infers that the 

 molecules are arranged in accordance with their fixed polarities 

 or cohesive attractions. So far as scientists can tell, the ar- 

 rangement of the molecules in crystals has nothing to do with 

 the function to be served by such an arrangement. Indeed, 

 one form of crystal is apparently as good as another so far as 

 the matter of the crystal itself is concerned. Unlike energy 

 and matter, life is a variable, and full of purpose. It, there- 

 fore, cannot be either matter or energy. 



2. Life manages matter through energy. 



Living protoplasm is a puzzle to the chemist and the physi- 

 cist. They do not find in matter associated with life the cer- 

 tainty that exists in the mineral world. The chemist believes 

 that there are several kinds of molecules in protoplasm, but 

 he is not sure how many. He knows the kinds of atoms in the 

 molecules, but he does not know the number of atoms of each 

 kind. The living protoplasm of plant cells can manufacture 

 sugar, starch and fats from water, carbon dioxide and sun- 

 shine, which is far more than the chemist can do. Many chem- 

 ical changes, such as oxidation of sugar and fats at ordinary 

 temperatures, are only possible to the chemist at much higher 

 temperatures. The chemical changes wrought in digestion, 

 assimilation, and in the preparation of a myriad organic com- 

 pounds, including the proteins, are mostly far beyond the 

 ability of the chemist to produce or induce. 



In a protoplasmic cell the molecules and groups of molecules 

 have no fixed arrangement so far as is known to the physicist, 

 nor are the cells rigidly grouped in the tissues, nor have the 

 tissues and organs the same arrangement in different plants 

 and animals. Furthermore, there is ceaseless change in living 

 protoplasm. As the work of the cell proceeds, molecules are 

 changed in composition ; matter no longer useful is excreted, 

 and new matter is absorbed and built into the cell structure in 

 accordance with the needs of the cell in doing its work. 



