Council Directive 78/55/EEC of 19 December 1977 amending Directives 66/400/EEC, 66/401/EEC, 66/402/EEC, 68/193/EEC, 69/208/EEC, 70/458/EEC and 70/457/EEC on the marketing of beet seed, fodder plant seed, cereal seed, material for the vegetative propagation of the vine, seed of oil and fibre plants, vegetable seed and on the common catalogue of varieties of agricultural plant species