equally divided among "small, medium, and large" classes in terms of

 weekly volume (Table 4). The seven retail firms with weekly sales

 over 1,250 crates accounted for 61 percent of the volume reported by

 all retailers contacted. By contrast, the "large" wholesalers

 accounted for 95 percent of volume by all 14 wholesale firms.

 Individual firms in a particular market area showed considerable

 differences in the share of total produce sales accounted for by

 celery, and in average weekly celery volume per store. However,

 weighted averages of the celery share of produce sales and weekly

 store celery volume showed essentially no differences between market

 areas (Table 5).

 Based on the preceding information on market structure and charac-

 teristics, it is probable that the firms interviewed accounted for a

 major share of celery in important market areas. The larger firms,

 who bought nearly all their celery directly from shippers, accounted

 for the largest share of celery sales, and average weekly volume per

 retail store differed little between market areas.


 Table 2.--Retailers included in study: number of firms, number of stores,
 share of grocery sales in market area, and total weekly
 celery volume

Market Area Firms Stores Share of Grocery Total Weekly
 Sales in Market Area Celery Volume
 No. No. Percent Crates

Philadelphia 6 387 59 5,100

Boston 8 507 53 6,900

Detroit 5 513 71 7,300

 Total 19 1,407 -- 19,300