Animalcules observés dans les matières purulentes et le produit des sécrétions des organes génitaux de l’homme et de la femme.

First description of Trichomonas vaginalis, which Donné at first believed to be the pernicious agent in gonorrhoea. He later recognized that the organism is a normal inhabitant of the female genital tract. By this work Donné was the first to describe living organisms in pathological conditions, as observed by modern methods. English translation in Kean (No. 2268.1).