vm 



PREFACE 



are embodied in this book. Other field assistants 



whose work deserves commendation are Mr. Ben 



Bairos, Mr. E. H. Cornell, Mr. E. O. McGregor, Mr. 



Herbert Leak, Mr. W. M. Davidson, Mr. Edward 



Barber, and Mr. Arnold Weber. To these and to my 



laboratory assistant, Mr. A. B. Shaw, Jr., I wish to 



extend heartiest thanks. 



W. B. HERMS. 



Berkeley, California, 

 April 4, 1912. 



