A national legislative measure prohibiting the keeping on an island such as Læsø of any species of bee other than the subspecies Apis mellifera mellifera (Læsø brown bee) constitutes a measure having an effect equivalent to a quantitative restriction within the meaning of Article 30 of the EC Treaty. A national legislative measure prohibiting the keeping on an island such as Læsø of any species of bee other than the subspecies Apis mellifera mellifera (Læsø brown bee) must be regarded as justified, under Article 36 of the Treaty, on the ground of the protection of the health and life of animals.