PREFACE 



XI 



also to make special mention of the indefatigable in- 

 dustry, wisdom, tact, and judgment of our field workers 

 who have gathered these facts and whose results, al- 

 though continually checked up, have stood every test 

 put upon them as to their accuracy and value. 



The work on this particular family has been done by 

 Elizabeth S. Kite, to whom I am also indebted for prac- 

 tically all of Chapter IV. 



I am also greatly indebted to my assistants in the 

 laboratory, for help in preparing the charts, keeping 

 the records, and correcting manuscript and proof. 



To Superintendent Edward R. Johnstone, whose 

 wisdom and foresight led to the establishment of this 

 Department of Research, whose help, sympathy, and 

 encouragement have been constant throughout the 

 work of preparing this study, the thanks and grati- 

 tude of the entire group of readers who find in these 

 facts any help toward the solution of the problems 

 that they are facing, are due. 



HENRY H. GODDARD. 



VlNELAND, N.J., 



SEPTEMBER, 1912. 



