Epidermis
It is a single-layered and it is made up of columnar cells.
Most of it’s cells are called as supporting cells. Some of the cells modify to form gland cells which are of two types-
- Mucous gland cells—They are found uniformly distributed all over the body. They secrete mucus to keep the body moist.
- Albumin gland cells—They are less in number and they secrete albumin. Most of the albumin gland cells are found in the body wall of the clitellum.
- Some of the epidermal cells modify to form sensory cells. In addition, the epidermis also has few basal cells which are small and round /cone-shaped.