CAUSE OF HEREDITY 281 



do some cells know how to do this work in the body and 

 some another kind of work? I stated before that the nu- 

 cleus contained the crowds of skilled workers, who are 

 informed and trained in all the work necessary to build 

 the entire animal. There is evidently in the nucleus of 

 every germ cell a multitude of primordial cells with spe- 

 cific training- for each specific department of work to be 

 done in the body, such as brain work, digestive work, 

 muscle work, respiratory work, etc. When the cell under- 

 takes to perform some specific work, for instance a brain 

 cell or liver cell, he has no use for those other skilled work- 

 ers in the nucleus that are not necessary to help him in his 

 department, and so they are excused from further service. 



This was a very important discovery, and Mr. Wilson 

 has the following to say in this matter : "Boveries' re- 

 markable observation on the nuclei of primordial germ 

 cells demonstrates the truth of this view in a particular 

 case, for here all the somatic nuclei lose a portion of their 

 chromatin and only the progenitors of the germ nuclei 

 retain the entire ancestral heritage. Boveries himself has 

 in a measure pointed out the significance of his discovery, 

 insisting that the specific development of the tissue cells 

 is conditioned by specific changes in the chromatin that 

 they receive. It hardly seems possible to doubt that the 

 limitation of the somatic cell in respect to the power of 

 development arises through a loss of particular portions 

 of the chromatin. Its application to development be- 

 comes clearer when we consider the nature of the 'nuclear 

 control' of the cell, i.e. the action of the nuclei upon the 

 cytoplasm." 



This goes further to prove what a highly organized and 

 specialized individual the cell really is. Just consider 

 its actions! In the first place, each new one takes his 

 place as it multiplies. One group stations itself where 



