PREFACE. 



At a time when so manj' books are appearing in Nature 

 Study, some sort of apology is due for proposing to add another 

 to the hst. There is some extenuation in the fact that the book 

 was not premeditated as such. What is here presented began as 

 a series of oral lessons by one of the authors given to classes of 

 children. These lessons were afterwards put into manuscript 

 form for the use of the Oakland (Cal.) schools, later they were 

 used as leaflets printed by the Oakland School Department, and 

 finally were included in the report of Supt. J. W. McClymonds. 

 Finally, answering an apparent demand for a wider use of the 

 lessons, both the authors revised and extended the lessons and 

 had them illustrated by competent artists, and a part of the papers 

 under the new form were published in the Western Journal of Edu- 

 cation. Since the publication of the series in the Journal began, 

 there has seemed to be a demand for the lessons that justified 

 gathering them together in this more convenient form. 



The selection of the particular topics here included is not to be 

 interpreted as an opinion of the authors that they are the essential 

 topics, or that they are the most important, since it is evident that 

 a number of lists of equally important or interesting objects could 

 be made. They have been selected as the result of long contin- 

 ued experimenting with children in different grades of the public 

 schools. If merit attaches to this list, it is that the topics in it 

 have been used as here treated with success, repeatedly, in the 



