In their disposition they are either uniserial, biserial or multiserial.
Driesch, in which, however, the primitively uniserial arrangement becomes masked later by secondary torsions of the hydranths.
The polyp may then form a second bud, which becomes the starting point of a new system, the beginning, that is, of a new branch; and even a third bud, starting yet another system, may be produced from the same polyp. Hence the colonies of Calyptoblastea may be com plexly branched, and the bud ding may be biserial through out, uniserial throughout, or partly one, partly the other.
- Diagram of sympodial 18) there is formed a main stem budding, uniserial type, shown on tithe i ma in t emeafh r m s polyp in four stages (1-4).