THE SIMPLEST LIVING THINGS 203 



reduced to half (that is, twelve) in the daughter cells 

 resulting from the division. Accordingly, when the 

 fusion of egg-cell and sperm-cell occurs each bringing 

 twelve V-shaped pieces the proper number is re- 

 established, namely, twenty-four. In the first division of 

 this fertilised germ-cell the cell resulting from the 

 fusion of egg-cell and sperm-cell the V-shaped nuclear 

 pieces split in the regular way, and the first two embryo- 

 cells are formed, each with its twenty-four pieces. Each 

 of these cells undergoes the regular process, and so by 

 continued growth and division into two an immense 

 series of cells are produced, which may separate as they 

 form, or in the case of multi-cellular creatures, remain in 

 continuity with one another as a bulky plant or animal. 

 Clearly the whole process arises from the value to the 

 growing mass of protoplasm of having its substance 

 closely sown or dotted with centres of nuclear matter 

 that specially active, co-ordinating material and of 

 having those centres of equal volume and quality ; and, 

 lastly, of having that nuclear matter equally, or nearly 

 equally, derived from the male and female parent, It is, 

 however, not certain from observation of what occurs 

 when the twelve male and twelve female V-shaped pieces 

 (or whatever the number may be in any given animal or 

 plant which have become grouped together in the 

 fertilised germ-cell) split and separate to form the 

 nucleus of two new cells that exactly twelve male and 

 twelve female pieces go into each of the new cells. It 

 is certain that twenty-four pieces go into each, but 

 although it is possible that exactly half of them are male 

 and half female in origin, it is not certain from observa- 

 tion that this is necessarily so. Supposing different 

 proportions to obtain in each of the two first embryo- 

 cells, it would help to account for the facts that offspring 

 are not an exact blend of their parents in all their 



