Article révisé par les pairs
Résumé : With the use of the electron microscope, nongerminal cells of Xenopus laevis ovaries were observed, fixed at metamorphosis time. ''Natural'' females were used; when the reared animals are treated with estradiol, numerous toads show intersexual gonads at this time. 5 Different nongerminal cellular types were observed in these ovaries: fibroblasts, prefollicular and follicular cells, macrophages, mastocytes and melanocytes. The cells of the 2 first types are very numerous and must be important relatively to the total ovarian mass. Tritiated uridine is strongly incorporated by these 2 cell types. This should be taken into account in any biochemical analysis bearing on whole ovaries at this stage, especially when devoted to RNA metabolism.