A fitment for use as a pour spout for a paper carton or flexible bag for liquids and powders has a flange which may be welded around a hole in the carton or bag. A spout projecting outward from the flange is provided with a removable membrane integral with the interior of the spout. Preferably the membrane is concave. A horizontally disposed pull ring is attached to the membrane by a connector so that pulling the ring removes the membrane by fracturing the tear line at the juncture of the outer edge of the membrane and the projection. A cap snaps over the spout and may be removed by unscrewing the complementary threads on cap and spout. Optionally, a tamper-evidencing band frangibly connected to the lower edge of the cap skirt engages the exterior of the spout so that the cap cannot be removed without breaking the frangible connection. Various means for detachably securing the fitment to a spud during delivery of the fitment from a chute to the interior of a carton are disclosed.