The blood cells are important members of the cell-community, and are exceedingly numerous, there being over 75,000,000,000 of the red-blood cells alone. These red-blood cells move in the blood currents, carrying through the arteries each its little load of oxygen which it transports to the distant tissues that they may be invigorated and vitalized anew; and, returning, carrying through the veins the debris and waste products of the system to the great crematory of the lungs where the waste is burnt and thrown off from the body. Like the ships that sail the sea, each cell carries its outgoing cargo, and returns with another one. Some of these cells perform the office of special repairers, forcing their way through the walls of the blood-vessels and penetrating the tissues in order to perform their special tasks. There are several other kinds of cells in the blood besides the carriers just mentioned. There are the wonderful soldier and police cells which maintain order and fight battles when necessary. The police cells are on the constant lookout for germs, bacteria and other microscopic disturbers of the peace of the body. When these tiny policemen discover vagrant germs, or criminal bacteria, they rush upon the intruder and tying him up in a mesh, proceed to devour him. If the intruder be too large or vigorous, a call for assistance is sent out, and the reserve police rush to the assistance of their brothers and overpower the disturber of the peace. Sometimes when the vagrants are too numerous, the policemen throw them out from the body, by means of pimples, boils and similar eruptions. In case of infectious diseases, an army corps is ordered out in full strength and a royal fight is waged between the invading army and the defenders of home and country. Some of the blood cells take a part in the process of extracting from the food its nourishing particles, and then carrying the same through the blood-channels to all parts of the body, where it is used to feed and nourish the stationary cells there located. These cells manufacture the chemical juices of the body, such as bile, gastric juice, pancreatic juices, milk, etc., in short the entire physical process is carried on by these indefatigable tiny cells. The body of each of us is simply a great community of cells of various kinds. The cells are born by the form of reproduction common to all cells, that of sub-division. Each cell grows until a certain size is reached, when it assumes a "dumb-bell" shape, with a tiny waist line, which waist is afterward dissolved and the two cells move away from each other. In this way, and this way alone, does the body grow, the material required for the enlargement of the cell being supplied from the food and nourishment partaken by the individual. Cells die after having performed their life-work, and their corpses are carried through the veins by the carrier cells, and cast into the crematory of the lungs where they are consumed.