Abstract
The chromosomes of 27 animals belonging to 11 species of the genus Cercopithecus were studied.
The number of chromosomes for the different species studied, varies from a minimum of 2n=54 to a max. of 2n=72. In individuals belonging to the same species, a different number of chromosomes has been noted.
The morphological analysis did not reveal any clear relation between the total number of chromosomes and the number of acrocentric chromosomes.
The total length of the caryotype measured on 20 metaphase plates, increases with the increase of the number of the chromosomes.
On the basis of these two data I suggest the hypothesis that the variation in the number of the chromosomes of the genus Cercopithecus is originated by the reduplication of single chromosomes.