a1 From the Molteno Institute for Research in Parasitology, Cambridge.
1. Embadomonas blattae a new species from the hind gut of Blatta orientalis is described. The flagellate measures 6–9 μ × 5–7 μ and the cysts 5–6 μ × 4–5 μ.
2. An Embadomonas from Rana temporaria, Bufo vulgaris, and Salamandra maculosa has been cultivated and described. I propose to call it E. dobelli. It differs from other known species of this flagellate in shape, and in absence of a definite karyosome. The flagella and their basal granules are duplicated first at division, and a centrodesmose is formed between one of each pair of basal granules. The cytostome disappears and new ones are reorganised after nuclear division is completed. Definite chromosomes were never seen. Double individuals and occasionally individuals with three nuclei were seen.
3. Cysts of E. dobelli were obtained in culture. They are uninucleate. A karyosome is formed; the peripheral chromatin of the nucleus stains intensely and becomes elongated. The lip of the cytostome can often be distinguished, and sometimes the glagella. These cysts are the same as those described originally by Dobell as cysts of Eutrichomastix batrachorum and Trichomonas batrachorum.
4. Cysts of Trichomonas batrachorum have never been found in faeces or in cultures.
(Received February 20 1931)
Beit Memorial Research Fellow.