[Hamann subsequently withdrew these statements.]
Leuckart, The Parasites of Man, English Trans. by W. E. Hoyle, Edinburgh, 1886, p. 56.
O. Bütschli, Zeitschr. wiss. Zool. Bd. xxvi. 1876, p. 103.
O. Hamann, Centrlb. Bakter. vol. xi. 1892, p. 501.
Zeitschr. wiss. Zool. vol. xxiii. 1873, p. 402.