[Comparison of soluble antigens of 2 cultured clones, of different age, from the same strain of a flagellate parasite: Trichomonas vaginalis Donné, 1837].

Antigenic analysis released indications that there seemed to be a qualitative difference between two clones (A2, A3) as well as between a young clone A2 and an old one (the latter having been in culture for 12 months) both of them originating from the same initial clone. Such differences are reduced to quantitative level by the results of cross absorptions. Antigenic variations mentioned by the previous authors are to be questioned.