In the middle ectoderm cell are seen a nucleus and three nematocysts, with trigger hairs projecting beyond the cuticle.
The cnidoblasts are the mother-cells of the nematocysts, each cell producing one nematocyst in its interior.
A third point of dispute is whether the nematocysts ar:e formed in situ, or whether the cnidoblasts migrate with them to the region where they are most needed; the fact that in Hydra, for example, there are no interstitial cells in the tentacles, where nematocysts are very abundant, is certainly in favour of the view that the cnidoblasts migrate on to the tentacles from the body, and that like the genital cells the cnidoblasts are wandering cells.
- Diagrams to show the structure of Nematocysts and their mode of working.
The nematocysts of the ectoderm may be grouped to form batteries on the tentacles, umbrellar margin and oral lappets.
How would you define nematocysts? Add your definition here.