 The wholesaler tenants of the building were stockholders of PF&PB.All the leases contained a clause under which the tenants agreed not to "transfer or permit to be transferred any interest in the business" without PF&PB's permission.Gamco, because of financial difficulties, borrowed money from Sawyer & Co., another wholesale fruit and produce dealer (apparently considered a price cutter) whose business was primarily in Boston, and the Gamco shareholders pledged their stock as security.