Ibid. p. 123.
Quart. J. Micr. Sci. xxxiii. 1892, p. 147. The experiment was conducted in a laboratory, and the results may not be perfectly normal with regard to the time occupied.
See also Joliet, Arch. Zool. Exp. vi. 1877, p. 202, and explanation of plate viii. for another series of observations.
See especially G. J. Allman, Monograph of the Fresh-water Polyzoa, Ray Society, 1856, p. 41; and H. Nitsche, Zeitschr. wiss. Zool. xxi. 1871, p. 479.
Ray Society, 4to, 1856.