Note 56 — PART II.

The male salmon is known to breed at a very early age. The Triton and Siredon, whilst retaining their larval branchiæ, according to Filippi and Duméril (‘Annals and Mag. of Nat. Hist.,’ 3rd series, 1866, p. 157) are capable of reproduction. Ernst Haeckel has recently (‘Monatsbericht Akad. Wiss. Berlin,’ Feb. 2nd, 1865) observed the surprising case of a medusa, with its reproductive organs active, which produces by budding a widely different form of medusa; and this latter also has the power of sexual reproduction. Krohn has shown (‘Annals and Mag. of Nat. Hist.,’ 3rd series, vol. xix., 1862, p. 6) that certain other medusæ, whilst sexually mature, propagate by gemmæ. See also Kolliker, ‘Morphologie und Entwickelungsgeschichte des Pennatulidenstammes,’ 1872, p. 12.