Observations upon a “Trichomonas” from Pond Water

Abstract

1. “Trichomonas” keilini n.sp. has three anterior flagella, and a short undulating membrane, whose bordering flagellum does not become free. The flagella arise from an anterior blepharoplast. There is a single nucleus, anteriorly placed, and a mouth, but no basal fibre to the undulating membrane. An axostyle may be present or absent, but when present it is siderophilic. The method of multiplication of “T.” keilini is similar to that of T. hominis and T. batrachorum.2. “T.” keilini was found in water from a pond in Lincolnshire.3. It has been cultivated in serum-saline media, in hay infusion, and in pond or rain water with boiled wheat grains, from 4 to 31° C.4. Cysts have never been found.I should like to record my gratitude to Prof. Keilin, F.R.S., who gave me the sample of water in which I first saw the organism, and who gave me encouragement throughout this study; and to Mr Clifford Dobell, F.R.S., for the gift of the macaque-human strain of Trichomonas and for so kindly reading through and criticising this manuscript.