334 Life and Health 



permitted in other branches of science in secondary schools, it by no 

 means follows that we are shut out altogether from this most impor- 

 tant and interesting part of the study. However simple and crude 

 the apparatus, the skillful and enthusiastic teacher has at his com- 

 mand a wide range of materials which can be profitably utilized for 

 experimental instruction. 



The subject-matter as set forth in the preceding chapters of this 

 book should be mastered, of course, but at the same time the topics 

 discussed should be illuminated and made more interesting and prac- 

 tical by the series of experiments given in connection with the several 

 chapters, a goodly show of specimens, and a certain amount of micro- 

 scopical work. 



4. Costly Apparatus by no Means Necessary. It will be noticed 

 that many of the experiments in this book can be performed with 

 very simple and often crude and homemade apparatus. This plan 

 has been rigidly followed by the author, first, because he fully realizes 

 the limitations and restrictions of the subject ; and secondly, because 

 he wishes to emphasize the fact that expensive and complicated appa- 

 ratus is by no means necessary to illustrate the great principles of 

 anatomy and physiology. 



In schools in which both the funds and the time for experimental 

 work are limited, the zeal and ingenuity of teachers and students are 

 often put to a severe test. Fortunately, a very little money and a 

 great deal of ingenuity and patience will do much towards providing 

 a working supply of apparatus. 



5. Use of the Microscope. The appearance of the various struc- 

 tures and tissues of the human body as revealed by the microscope 

 possesses a curious fascination for every observer, especially for 

 young students. No one ever forgets the first look at a drop of 

 blood, or the circulation of blood in a frog's foot as shown by the 

 microscope. 



For elementary class work a moderate-priced but well-made and 

 strong instrument should be provided. If the school does not own 

 a microscope, the loan of an instrument should be obtained for at 

 least a few weeks from some person in the neighborhood. 



To do thorough and satisfactory work in physiology in our higher 

 schools a compound microscope is almost indispensable. Inasmuch 

 as many of our best secondary schools are equipped with a micro- 

 scope for use in other studies, notably botany, it is much less difficult 



