Throughout the body, heart, lungs, stomach, intestines, liver, muscles, and skin, all need one another's aid to obtain food and oxygen, to remove wastes, and to avoid dangers. This co-operation makes the individual human being ; a mere mass of living organs, arranged together in the form of man's body, but each acting without reference to the rest, would no more make a man than a mob of strong men would make an army. As in the mob the reckless courage of some, the personal cowardice of others, the uncontrolled ambition of a few, would make the crowd nearly useless for military purposes in spite of the merits of its individual members, so in the body; if the organs were not disciplined, controlled, and guided, so as to work together for the good of the whole, death would very soon result. As a matter of fact this is the way in which death almost always does begin. The body is not built like the deacon's "one-hoss shay," to run till every part of it gives out at the same moment. Some important organ ceases to do its part properly; as a consequence the whole complex mechanism is thrown out of gear, and deatn results.

Is co-operation between its organs general throughout the body? Is it important? Illustrate the importance of co-operation between the parts of the body.

For what purposes do the different organs need one another's help? Is the co-operation of organs necessary to make an individual human being? Illustrate.

Co-ordination means controlling the activities of a number of working things (whether men, or organs, or machines) for the attainment of a definite end. A promiscuous and undirected crowd of competent bricklayers, carpenters, hod-carriers, and so forth, would be quite incompetent to build a house. There might be present abundant energy and skill to construct walls and floors and roof; but if each man worked for himself and took no heed of the rest the result would be an odd building, if any at all. Hence the whole work is placed under the control of a master builder, who guides the activities of individuals according to the needs of the moment: undirected workmen, if conscientious, would work just as hard without supervision, but they would work unprofitably. The healthy body may be regarded as made up of a number of conscientious workers, the organs, who are concerned in building it and keeping it in repair, each one acting so as to co-operate with the rest for the attainment of the common end. The master builder, or "boss," if we may use such a word, is represented by the nervous system, which is in communication with all the other organs, is influenced by the condition and the needs of every part at each moment, and guides the activity of all the others accordingly. Part of this control is exercised consciously and with this co-operation of the "will," but much more is carried on by the nervous system without our knowing anything about it.

How does death usually begin? What happens when some important organ ceases to do its duty?

What is meant by co-ordination? Illustrate. How may the healthy body be regarded when compared with the workmen concerned in building a house!