2. The muscular system, which supplies the energy necessary for executing the movements of the body.
3. The nervous system, which (a) controls and coördinates the various activities and (b) provides for the intelligent adjustment of the body to its environment. (Review Summary of Part I, page 215, and consult Fig. 92, page 214.)
APPENDIX
Equipment.—Nearly all of the apparatus and materials called for in this book may be found in the physical, chemical, and biological laboratories of the average high school. There should be ready, however, for frequent and convenient use, the following: One or more compound microscopes with two-thirds and one-fifth inch objectives; a set of prepared and mounted slides of the various tissues of the body; a set of dissecting instruments, including bone forceps; a mounted human skeleton and a manikin or a set of physiological charts; a set of simple chemical apparatus including bottles, flasks, test tubes, and evaporating dishes; and a Bunsen burner or some other means of supplying heat.
The few chemicals required may be obtained from a drug store or from the chemical laboratory. Access to a work bench having a set of carpenter's tools will enable one to prepare many simple pieces of apparatus as they are needed.
Physiological Charts are easily prepared by teachers or pupils by carefully enlarging the more important illustrations found in text-books or by working out original sketches and diagrams. These, if drawn on heavy Manila paper, may be hung on the wall as needed and preserved indefinitely. By the use of colors, necessary contrasts are drawn and emphasis placed on parts as desired. The author has for a number of years used such home-made charts in his teaching and has found them quite satisfactory. His plan has been to draw on heavy Manila paper, cut in sizes of two by three feet, the general outline in pencil and then to mark over this with the desired colors. There is of course an opportunity for producing results that are artistic as well as practical, and if one has time and artistic skill, better results can be obtained. Many of the cuts in this book are excellently suited to enlargement and, if properly executed, will provide a good set for general class purposes.
Models.—The use of prepared models of the different bodily organs is strongly urged. These may be so used in elementary courses as to obviate much of the dissections upon lower animals. Although the actual tissues cannot be so well portrayed, the general form and construction of organs are much better shown. Models well adapted to class or laboratory work are easily obtained through supply houses. Illustrations of several of these are shown in connection with the "Practical Work."