200 HOW NATURE STUDY SHOULD BE TAUGHT 



if the intensity of treatment is made to vary ac- 

 cordingly. 



It is advisable, when possible, to plan a gen- 

 eral series or course for the year, considering the 

 kind of material that is readily accessible, or phe- 

 nomena that can be observed at successive dates. 

 Although class excursions for outdoor study are 

 very valuable when they are conducted with but 

 few persons, they cannot be relied upon with full 

 rooms, as many experiences have proved that they 

 are not at all practicable. Try them, and under 

 certain conditions field excursions may be found 

 a valuable feature of nature study. These es- 

 sential conditions are (i) that a suitable time be 

 found for such excursions ; (2) that the size of 

 the class be reduced to a number that can be 

 handled to advantage in the field, usually not 

 more than fifteen ; (3) that the teachers know 

 where and how to go, and what to do and how to 

 do it. Although there are so many contingencies 

 here outlined that it appears discouraging, it is 

 far better for our readers that these conditions be 

 pointed out, than that they should have to learn 

 them by the actual, sad experiences that have be- 

 fallen teachers and parents in various places, who 

 have attempted to follow the many impracticable 



