Burrows: Study of Body Cells. 479 



birth or thereabouts. Subsequent to this time hfe is merely an ex- 

 pression of the gra(hial deterioration of the previously built hetero- 

 geneous system or the interaction of its various parts, which follow 

 tlie law for the disintegration of all such heterogeneous systems. 

 Life of the animal ends with the establishment of an equilibrium be- 

 tween the parts of the organization which produce the work that 

 really constitutes life. The energy for the building of the first 

 period is derived, therefore, in the later period. 



Systemic or general death is nothing more, therefore, than the 

 establishment of a true equilibrium, or a breakdown in one of the 

 essential parts of the body. This is not the end, however. What 

 we have been talking about so far is the life of the organism, and 

 not that of the cell. The end of the individual does not mean the 

 end of all its parts. The cells are not dead at this period. They are 

 all intact. This system is able to reproduce itself. The normal 

 death of the whole is not the result of the death of the cells. The 

 cells which make up the whole are destroyed, rather, by the process 

 of the death of the whole. These cells, as we now know, go on for- 

 ever under the proper circumstances. Out of one of them in the 

 old, the egg cell, comes a new individual. Their destruction at the 

 death of the individual is the result of this general death. Their 

 destruction is the result alone of their position. Systemic life and 

 systemic death are something different, therefore, from elemental 

 life and elemental death. The first has limits; the other may have 

 none. The question is. What is the nature of this system which can 

 show such changes? This cannot be solved by a study of the animal 

 as a whole. It cannot be solved by the study of the amoeba, be- 

 cause it is an animal itself. It must be solved through a study of 

 those cells which go through these changes, those cells which find 

 this building of an animal and the ultimate disintegration of this 

 animal their normal means for preserving their kind. The amoeba 

 need take no such complicated route to preserve its kind. These 

 cells of the animal must take this course in order that they survive 

 and that the proper environment be prepared for their reproduction. 

 Child has ignored this fact completely. He has assumed a continu- 

 ous dynamic state for the cell without any proof of its existence. 

 He has again assumed that the life of the whole is only an elabora- 

 tion of the life of the cell. He has assumed differentiation to be a 

 peculiarity of all cellular life. He has assumed the protoplasm of 

 cell to have structure capable of performing work. The best bio- 

 logical work of the last century has not only added no proof for 



