THE CELL 71 



within the cell and multiplies by division in the same 

 manner as the cell itself. 



We shall now consider the functions of another im- 

 portant organ of the cell, the nucleus. This consists of a 

 crowd or colony of skilled workers, who perform, look 

 after and direct the different kinds of work. You will see 

 later on, that the nucleus has a number of crowds or col- 

 onies specialized in different kinds of work. These col- 

 onies are called chromatin granules or grains and when 

 lined up for division are called chromosomes. 



Here is a description of the nucleus by Prof. Wilson : 

 "The nucleus usually lies in the center, but as the outer 

 wall thickens the nucleus moves toward it and remains 

 closely applied to it throughout its growth, after which 

 the nucleus often moves into another part of the cell. 

 That this is not due simply to a movement of the nucleus 

 toward the air and light is beautifully shown in the inner 

 walls of the cell. The same position of the nucleus and 

 movement of the nucleus is shown in all cases toward the 

 place or near the place where the work is to be done." 



I wish to make it clear to the reader that in the con- 

 struction of any product in the body like bile, milk or 

 digestive fluids, it is not produced by the gland, liver, 

 etc., but by the individual cells of which they are com- 

 posed ; and that these individual cells are again made up 

 of still smaller individuals, who do the actual work. You 

 see the cell itself is a very highly organized being, just 

 as the human body. The cells that build our body were 

 not always in the habit of building themselves into large 

 co-operative colonies like those we see now as animals, 

 plants and trees. We find them still with other habits 

 and methods of life, living the single and separate lives 

 in ocean or fresh water and nearly all of them have some 

 peculiar ways and actions that show wonderful skill and 



