234 Journal of Agricultural Research voi. xix, No. s 



But since the "breeding centers" have been a factor for at least 20 years, 

 and doutless the "experimental laboratory" has been in operation a 

 good part of that time, the continuation of the plan attests its efficiency. 

 By adopting the individual as the unit we eliminate the probable inac- 

 curacy of pen averages and hope to have taken at least one step in devising 

 a practical method for measuring the efficiency of meat-producing 

 animals. 



