[Cytogenetics of two Lorisidae (Nycticebus coucang and Perodicticus potto). Comparison with the lemurs and the simians (author's transl)].

The karyotypes of two Lorisidae (Prosimians) Nycticebus coucang and Perodicticus potto have been studied, using many banding techniques. These karyotypes are compared with each other and also with those of Microcebus murinus (Lemur) and of Cebus capucinus (Simian, platyrrhine). The karyotype of M. murinus appears ancestral to the other. That of the Lorisidae cannot be an intermediatry stage between the karyotypes of the lemurs and of the simians. An important part (12 p. cent) of the genome of N. coucang is comprised of heterochromatin ; it and the juxta centromeric heterochromatin stain negatively with C-banding techniques. C-banding therefore is insufficient to delineate constitutive heterochromatin, late replication being the only universal criterion.