Oogenesis and mode of reproduction of a population of Radopholus similis attacking plantains in Puerto Rico was studied in the laboratory In the germinal zone of the ovary, the chromosomes, although very indistinct, divided by mitosis, and the chromosome complement was 2n = 10. Oocytes did not advance beyond metaphase I unless penetrated by a spermatozoon. Then, the first polar body was formed where the chromosome number was n = 5. Maturation of the oocyte terminated with the formation of the second polar body. Inoculations of carrot discs with one or two larvae of R. similis respectively showed that, 60 days after inoculation, the reproduction was found only in the latter treatment, demonstrating that amphimixis had taken place, and apomixis did not occur.
