320 The Morality of Nature 



in the parallel search for the mechanism of heredity, and 

 for the determination of sex, and for the nature of psycho- 

 logical phenomena, and of consciousness, there are only the 

 beginnings of sure knowledge. Yet these broken begin- 

 nings give a structure of fact, which it is fair to fill with 

 reasoned hypothesis, so that the general meaning may be 

 brought out. We are here seeking the ethical import of 

 biology, and not exact biological science for itself. In this 

 effort we may occasionally use a provisional theory to get 

 a comprehensive grasp of the subject. The unity of com- 

 pleteness can be realized in this and in no other way. The 

 postulate thus used to complete the story of biology where 

 facts temporarily fail, is confessedly to be supplanted by 

 sure knowledge in due course. 



The great achievement of biology and that at which we 

 must approach it, is the revelation of the all composing 

 cell. 



Living matter, above the stage of the primal shapeless 

 masses, is found to be, always and without exception, 

 organized into form as a cell. Every such living thing is 

 a cell, or is built up of a number of cells. No life appears 

 except as a cell, arising from a parent cell, and for a com- 

 pound creature, multiplying into cells of greater or less 

 number, until its ordered form is reached. This is a simple 

 statement of well-established fact. A human being and a 

 protozoon are alike examples of the fact. It has been 

 calculated that the human body is constructed of twenty- 

 six thousand billion cells, all descendants from the original 

 one, which was, in the beginning, organized in the same 

 plan as the protozoon whose one cell is its maturity-form. 



