be wise to delay making the change until it is determined that the 

 new standards which are being established by the Food and Drug Admin- 

 istration in cooperation with the tuna industry do not lead to further 

 changes in the style of pack. In order for an index series to be of 

 value, it is necessary that the series have a list ofsitems which is 

 not changed too often. Otherwise, the index will lose its value be- 

 cause of defects in comparability. 



3S6 



