132 ENERGY TRANSFORMATIONS IN LIVING MATTER 



that if there is any tendency to accumulation of biotic energy, the 

 capacity factor being fixed by the size of the cell, the potential 

 factor must increase and lead to division and reproduction. 

 Naturally any such process must be modified by other factors 

 playing in upon the cell, such as food, temperature, and other 

 conditions of environment, but the process is guided and controlled 

 by the biotic energy of the cell. 



The division and reproduction of the cell, therefore, furnish 

 energy phenomena of a type not found outside living matter. 



III. Heredity, and the reproduction of like species from like, 

 shows that there is something present not dependent merely upon 

 structure, but that the cell possesses a type of energy which causes 

 a retention of properties, and a capacity for communication of 

 these onward. 



By variations in the factors of such a form of energy the 

 character of the effects is capable of alteration, much in the same 

 way as variation in vibration period can alter the effects produced 

 by radiant energy, or alterations in constituent groups of the 

 chemical molecule can alter the chemical energy. 



The closest histological examination reveals no essential differ- 

 ence between the ovum of one species of mammal and that of 

 another, yet the cells develop into widely different species. This 

 cannot all be due alone to the operation of inorganic forms of 

 energy upon cell structures so similar that the microscope can show 

 no difference in design. Nor can the unicellular ovum contain 

 already laid down in it structurally some representation of each 

 cell or even each tissue of the animal which is to be formed from 

 it. It is too minute and too simple in its organisation to render 

 such a view tenable. Nor is the chemical composition of the 

 complete animal represented in that of the early embryo. It is 

 evident that the course of cell division and development by which 

 a constant species is arrived at is not attained by means of structure 

 in the embryo, the ingress of chemical energy from without, and the 

 action of diffusion and osmosis. But if there be added to these 

 the presence of a distinct type of energy peculiar to living matter 

 which controls and regulates the energy phenomena of the growing 

 embryo, and which is attuned initially to the species of living creature 

 to which the embryo belongs, then a more feasible basis for the ex- 

 planation of the course of development of the individual becomes 

 apparent. At each step this biotic energy will regulate the growth 



