Ink cartridge and printer

A printer comprising:

• a recording head;
• and
• an ink cartridge attachment portion, to which an ink cartridge can be detachably attached, extending from an opening to a back end, the ink cartridge attachment portion comprising an agitation-member drive unit configured to engage with and drive an agitation member of such an attached ink cartridge,
• wherein a fixed spout, arranged on the ink cartridge, and the agitation-member drive unit are both arranged at the back end of the ink cartridge attachment portion when the ink cartridge is engaged with the ink cartridge attachment portion, and wherein the fixed spout is welded to an ink storage bag and the weld is a fulcrum for the ink storage bag and the fixed spout, and
• wherein, when the agitation member operated by the agitation-member drive mechanism agitates the ink, a free end of the ink storage bag is swingingly moved.