36 NATURE-STUDY 



animals, natural or manufactured products of plants, animals, 

 or minerals, geological specimens, astronomical and meteoro- 

 logical phenomena and experiments are all included in this 

 class of illustrations — the actual thing. They are the most real. 

 Of less value than actual objects, but still of great value, 

 are the following representative illustrations. 



Models, Pictures, and Diagrams 



Models of sand, clay, or other plastic material are very 

 useful in geography. Anatomical casts are excellent in the 

 study of physiology. The dissectible kind are especially 

 instructive and give an idea of internal anatomy. Models of 

 geological sections to illustrate the strata of the crust of the 

 earth are very good. Again, a properly constructed working 

 model of a machine or other physical apparatus adds to 

 the interest in the lesson and helps to explain. 



Pictures may be used in lieu of other illustrations and, if 

 well selected, may be very effective. In this day of wonderful 

 reproductive processes by photograph, half-tone, and color 

 photography, pictures furnish excellent illustrations in nature- 

 study. Children naturally love them and are interested 

 in their every detail. Pictures leave for a long time a definite 

 image in the visional memory. The nature-study teacher 

 may secure them from many sources. Animal pictures are 

 to be found in natural histories, zoologies, and animal readers; 

 and plant pictures are found in botanies, garden books, etc. 

 The teacher should make a nature-study picture scrap-book, 

 by cutting out illustrations from old geographies, zoologies, 

 botanies, and other text-books, and from magazines and 

 papers. Let the children also do this. Colored pictures 

 are the best, providing the colors are true to nature, which 



