Abstract: The novel combination comprising:a container having a cylindrical neck of reduced cross-section terminating in an open end, said neck having a projection on its inner surface in proximity to said open end, anda closure for said open end having a skirt portion receivable in said open end and a shoulder at its outer end adapted to move into abutting relationship with the end of said cylindrical neck, said skirt portion having a cut out adapted for receiving said projection on the inner surface of said neck to hold said shoulder in non-abutting relationship with the end of said neck, said closure including a central fluid passage and a transverse fluid passage in communication therewith, the ends of said transverse fluid passage being sealed by the inner surface of said neck when said closure is held in the non-abutting position by the engagement of said projection in said cut out, said engagement being adapted to be overcome by force applied to the end of said closure whereby said shoulder is brought into abutt