Abstract
The presence of only a single satellited chromosome in the chromosome complement of Allium cepa was recorded. By means of Giemsa staining, silver staining and C-banding, cytological studies of the chromosomes were carried out in bulbs with a single, two, three and four satellited chromosomes. The presence of the satellites was limited to the subtelocentric (st) and the shortest metacentric (m3) chromosomes. Although the satellites were higly polymorphic in size and staining intensity, all proved to be active for nucleolus formation as revealed by silver staining. The st chromosomes were easily discriminated into two types and the m3 into three types by C-banding. It is concluded from the present observations that both the translocation and deletion may be concerned in numerical variation of the satellited chromosomes and the polymorphism of the st and m3 chromosomes.