[General transmission of sigma virus in "Drosophila melanogaster". II. - Revelation of late vertical tansmission in females which have acquired the virus only by the father spermatozoon (author's transl)].

This report concern work with Drosophila melanogaster females, which have only acquired the sigma virus strictly vertically through the father spermatozoon. After than the 20th day of life, most of these show an increased frequency of infected progeny. These results obtained provide evidence that the phenomenon is similar to the classical "passing over to germen", described in sigma-drosophila relationships. They confirm that germ-line infection in non-stabilized females can only occur during oogenesis. In these females, oogonia are never infected.