All zooids in a colony are linked by strands of epithelial cells. The individual members of a colony, the zooids, are in some species generalised: they feed, and they can reproduce on occasion. But in most species the zooids are specialised to diffent functions. In this case the feeding zooids are called "autozooids", and the non-feeding members are called "heterozooids". Functions done by heterozooids include sexual reproduction, protection, locomotion, plumbing, structural support. The functions of some heterozooids is still unknown. The commonest function is that eggs are developed in brooding chambers ("ovicells") on female or hermaphrodite heterozooids. There are variations in the details: sometimes a little complex of heterozooids produce larvae in a cooperative effort.p4