94 CELL INTELLIGENCE THE CAUSE OP EVOLUTION 



first discharge or dispense with a part of their nucleus or 

 specifically skilled workers, according to the kind of work 

 they have to do. These facts are very significant in that 

 they prove that the nucleus contains groups of workers 

 specifically skilled in all the departments of work per- 

 taining to the building of the body. When a cell takes 

 charge of the work of building and maintaining the liver 

 or lungs it retains only that group of specifically skilled 

 workers who understand that particular line of work, 

 and discharges all the others. In reference to these facts, 

 I will here quote some more from Prof. Wilson : 



"The germ from which every living form arises is a 

 single cell derived by division of a parent cell of the pre- 

 ceding generation. In the higher types the germ cells 

 are more or less definitely organized in groups supported 

 and nourished by somatic cells, specially set apart for that 

 purpose, and forming distinct sexual organs, the ovaries 

 and spermaries, or their equivalents. Within these organs 

 the germ cells are carried protected and nourished and 

 here they undergo various differentiation to prepare them 

 for their future functions. The structural difference thus 

 brought about between the germ cells is, however, only 

 the result of physiological division of labor. The female 

 germ cell or ovum supplies most of the material for the 

 body of the embryo and stores the food by which it is 

 nourished. It is therefore very large and contains a large 

 amount of cytoplasm laden with food matter, and in many 

 cases becomes surrounded by membrane or other enve- 

 lopes for the protection of the developing embryo. On 

 the other hand the male germ cell or spermatozoon con- 

 tributes to the mass of the embryo only a very small 

 amount of substance comprising as a rule only a single 

 nucleus and a very small quantity of cytoplasm. It is 

 thus relieved of the drudgery of making and storing food 



