Publication details, including instructions for authors and subscription information:ABSTRACT: The essential oil content and composition in two newly-bred varieties of Chammilla recutita (L.) Rausch. (the diploid "Bona" and tetraploid "NL 9 0 ) were studied during ten distinguishable phases of anthodia development. The highest essential oil content was found in young anthodia. A comparison between the diploid and tetraploid varieties reveals that the tetraploid variety was proportionally richer in chamazulene than the hploid variety during the terminal flowering stages.