60 WHAT IS LIFE 



represent the strain figures of the cell, the cell 

 forces are distinct from any known physical force." 

 In other words the indications point to the fact 

 that the remarkable happenings which have been 

 described as taking place in the cell prior to and 

 during division are vital manifestations, since they 

 cannot be explained by any of the known forces of 

 physical science. 



We are now in a position to pass from this 

 part of the question and to consider another of no 

 Division of less interest. The first division of the fertilised 



ovum 



ovum had as a result the production of a two-celled 

 creature. Each of these cells again divides, so that 

 if division were always regular in its progression, 

 which it is not, we should have the two-celled stage 

 followed by one of four cells and that by others of 

 eight, sixteen, thirty-two, sixty-four and so on. 

 Such a progress of division does take place in some 

 cases, but in others differences, as to which nothing 

 can here be said, are exhibited. But whatever 

 may be the sequence of division the result is the 

 formation of a creature which from one cell has 

 developed into a multicellular organisation. It is 

 obvious that this multicellular organism might 

 consist of identical cells or of cells differentiated 

 from one another in groups so as to form different 

 organs. Such is the condition which is met with 

 in all the higher animals where, as, for example, in 



