180 NATURE STUDY. 



it, we see why interest and sympathy are so essential. 

 They are the only means of establishing the greatest 

 unity between the child and his environment. 



In the law of unity we find the psychological basis 

 for the greater educational value of the study of life, 

 the most nearly perfect illustration or realization of 

 physical unity. In a living plant or animal all parts 

 are organized to co-operate with one another, to work as 

 a unit in taking from environment, from sunlight and 

 soil and air, and in giving to environment. Perfect 

 physical life in plant or animal is perfect adaptation or 

 perfect relation or complete physical unity between it 

 and its environment, or that part of its environment to 

 which it is adapted or related. As this unity becomes 

 less complete, disease comes. When death ensues, unity 

 ceases. The plant or animal is no longer a unit, but is 

 disorganized, made up of isolated parts. In the study of 

 death, of mere form and structure, the child does not 

 see this unity, and his mind is not greatly aided in its 

 unifying process. In the study of leaves or roots or 

 stems or flowers, isolated and not related to the plant, 

 this psychological demand for unity is not recognized 

 nor satisfied. 



From this standpoint we see also the psychological 

 reason for emphasizing the study, in earlier years or 

 lower grades, of life and living nature, and of forces and 

 processes, and understand why the study of minerals or 

 of mere form and structure is not so interesting to 

 young children, and not so satisfactory in its results. 

 If in earlier years children can study units, the whole 



