B, a specimen undergoing fission (X 20).
Reproduction by longitudinal fission is habitual and frequent in this species.
In this way we may distinguish, first, vegetative reproduction, the result of discontinuous growth of the tissues and cell-layers of the body as a whole, leading to (I) fission, (2) autotomy, or (3) vegetative budding; secondly, germinal reproduction, the result of the reproductive activity of the archaeocytes or germinal tissue.
In some Syllids this posterior region separates off from the rest, producing a new head; thus a process of fission occurs which has been termed schizogamy.
Sooner or later, however, the scyphistoma produces free medusae by a process of transverse fission termed strobilization.
