238 ' ROBERT M. YERKES 



the value of the shocks may be expressed in terms of stimula- 

 tion units ; these units to be applicable to any properly con- 

 structed induction apparatus, and to be based upon determina- 

 tions which can be made in any ordinarily equipped physiologi- 

 cal laboratory. The system proposed is not a new departure, 

 but is an extension and amplification of previous systems." 

 (I.e., p. i and 2.) 



These statements apply to many investigations in behavior 

 and psychology as well as to more strictly physiological inves- 

 tigations. Dr. Martin's method is sufficiently simple to render 

 it easy to use and it should be carefully considered by all inves- 

 tigators who desire to do accurate work. * 



