THE WORKERS OF THE BODY. 137 



Glance through the body's constitution, and you 

 will find, first of all, that, wherever you have life and 

 vital activity, it resides in a particular kind of living 

 jelly which everybody knows (by name, at least) as 

 " protoplasm." This is the "matter of life" it is 

 life-stuff, in the truest sense ; since no other matter 

 on the face of this earth, save protoplasm, shows the 

 phenomena or actions of life. 



Now, what is true of a man's body in this respect is 

 equally true of the body of every other living thing 

 animal or plant. When we come to investigate how 

 this protoplasm (of a speck of which, the whole body 

 in its germ-state once consisted) is disposed in our 

 frames, we discover that it is represented in its most 

 active state by microscopic bodies to which the name of 

 " cells " is given. Here and there, the protoplasm has 

 been worked up to form fibres and other structures (as 

 in muscles and nerves) ; but the active, living elements 

 of our frames consist, undoubtedly, of cells. 



What, then, is a cell ? Imagine a speck of this 

 living matter, averaging, say, the one four-hundredth 

 of an inch in diameter, of rounded shape, bounded by a 

 kind of envelope, and having a particle (the nucleus) 

 somewhere or other imbedded in its interior and you 

 will have a fair conception of what a cell of ordinary 

 size and form is likely to be. Some cells we know 

 of nerve-cells, indeed average only the one five- 

 thousandth of an inch, or less, in diameter; and be- 

 tween big cells and little cells there are, of course, 

 all gradations in size. 



These cells, then, are the workers of the body. 

 They are the population of the vital kingdom. The 

 democrats are the cells -useful and necessary, and 

 respectable members of society which toil and labour 



