Trichomonas belongs to the flagellate infusoria. Buetschle1 says that about three species of Trichomonas are known. All are parasitic, living in the intestines of frogs, snails and other lower animals, and in the human vagina. Trichomonas vaginale was found in the vaginal secretions of women by Donné2 in 1836. While Donné's observations, though at first criticised, were finally accepted as true, yet it may be said that the parasites have been deemed of so little importance that they have until very recently received only scant notice.
Dock,3 of Ann Arbor, has just published a careful review of the literature bearing on this parasite in connection with the report of an extremely interesting case in which the trichomonas was found in the urine of a man. Dock's case seems to be the third undoubted case of this kind in the order of publication, and the first in this
TRICHOMONAS AS A PARASITE OF MAN.. JAMA. 1896;XXVI(9):437-438. doi:10.1001/jama.1896.02430610039008