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% Devoted to Elementary Science in The Schools 



OFFICIAL ORGAN OF THE 



American Nature-Study Society 



Photo by R. Matheson 

 BOB'S COCOON YIELDS ITS TREASURE 



The Nature Study Outline Number 



Vol. 17 No. 7 



OCTOBER, 1921 



20c a copy $1.60 a year 



Whole No. 147 



