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stration. To get at the facts that will settle such problems tests 

 must be skillfully made on hundreds of pupils. That they can not 

 be settled off hand on the basis of the teacher's general experience 

 the author has demonstrated to his own satisfaction. Some thirty 

 specimens of snail shells (Polygyra) belonging to several clearly 

 marked species were given to pupils with the instruction to "put 

 all the shells that are alike in one pile, having as many piles as there 

 are different kinds of shells." Lower grade children accomplished 

 the task with a very much smaller percentage of error than did 

 high school freshmen. In another test a small glass flask was used 

 which had fitted into its mouth a rubber cork through which 

 passed a tight fitting open glass tube. The lower end of the tube 

 dipped below the surface of some red liquid covering the bottom of 

 the flask a half inch deep. When the flask is held by the pupil so 

 its bulb is well covered by the hand, the heat expands the air the 

 pressure of which on the surface of the liquid causes the latter to 

 rise in the tube. The pupil is asked to tell what happens and why 

 it happens. Eighty-four per cent, of the seventh grade pupils 

 tested explained the phenomenon correctly, but only forty-one per 

 cent, of the college freshmen. Such unexplained and apparently 

 incongruous results simply indicate that the problem of fitting 

 nature-study and elementary science to the pupils' ability is no 

 small task. 



If science is a mass of generalizations organized on the basis of 

 experience, then it is important that the individual should be 

 brought to a grasp of the important generalizations as speedily as 

 possible, equipped to use them and possibly to add to them. Do 

 we spend too much time in merely accumulating sense impressions, 

 in acquiring unrelated percepts? What range of information is 

 already in the mind of the average child in a given grade? It 

 would pay us to find out by carefully conducted surveys that we 

 may know at what stage we may proceed to generalize on the basis 

 of the children's experience rather than repeat what the pupils 

 have already sensed. It is fairly evident from the well-nigh 

 universal statement of the content of nature-study courses in terms 

 of things rather than in ideas that the nature-study teacher is 

 more concerned with accumulating experience than with reaching 

 generalizations. This statement is not a criticism but a challenge. 

 We do not know the ground on which we stand and here is another 

 opportunity for investigation. We must know the content of 





