A GRADED COURSE OF NATURE STUDY. 331 



in drawing, writing, and reading to be done at some 

 other time. If less time is given to observation, very 

 little will be accomplished. 



To keep up the interest and obtain the best results, 

 these observation lessons should not be less than twenty 

 minutes, nor more than half an hour in length during 

 the first three years ; nor less than half an hour, no 

 more than an hour, during the later years. 



To facilitate the selection of matter and the arrang 

 merit of shorter courses, which, although covering less 

 ground, shall be in general accordance with the prin- 

 ciples stated in preceding pages, and shall be logical 

 and coherent, the topics in the accompanying course of 

 study are printed in three styles of type : Those which 

 are most important, and which, taken together, will 

 form a coherent short course, are printed in heavy-faced 

 type ; those which, in addition to the topics in heavy- 

 faced type, are considered essential for a longer course, 

 are printed in ordinary type ; those which may be con- 

 sidered as supplementary appear in italics. 



In beginning systematic science work it is impossible 

 of course to follow at first a graded course of study. 

 The work outlined for the upper grades requires and is 

 based upon the work in the lower grades. It is recom- 

 mended that, in beginning systematic science work, 

 during the first year all pupils in grades two to four 

 follow the work outlined for the second year, and all 

 pupils in grades above the fourth follow the work out- 

 lined for the third year, adding, in the upper grades, 

 such topics as may seem wise. 



