Induction par la température d'une physiologie mâle chez les néo-femelles et les intersexués du Crustacé OniscoïdeArmadillidium vulgareLatr., hébergeant un bactéroïde à action féminisante

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Abstract
In the Oniscoid Armadillidium vulgare, inside the thelygenic line of the Niort population, intersexed females, whatever their sizes, and most of the young neo-females from 5 to 6 mm long (males feminized by a polytropic intracytoplasmic bacteroid kept for 13— 47 days at 35°C, and then replaced at 20°C, are masculinized. The masculinization of their external sexual characters is more or less complete, and the ovary is changed into a functional testicle with one or several utricles, each of them having an androgenic neogland. This masculinization, which restores a phenotype corresponding with the genotype, goes with the disappearance of the typical forms of the bacteroid, such as they are observed in neo-females and the intersexed individuals kept at 20° C. Yet, this male physiology is only temporary: a female physiology is restored after the animals have been kept at 20° C for 2–4 mth, but the acquired male differentiation is maintained. This implies that special forms of bacteroids continue to exist and that, when the host is again kept at 20° C, they produce the typical feminizing factors. The absence of masculinization in neo-female adults is not due to the maintenance of the bacteroid, but to the impossibility of inducing the differentiation of an androgenic neo-gland after the 6th molt of the postembryonic development; the cells of the primal androgenic gland—which exist in all females—have then completely disappeared, or have definitively turned into conjunctival cells. Masculinization does not occur either in real young females (genetic females), which proves that temperature is only an indirect cause, and acts by inhibition of the feminization action of the bacteroid.