Explain the process of mating and the formation of the cocoon in earthworms.

(N/A) $1$. Mating: Earthworms are hermaphrodites,meaning they possess both male and female reproductive organs. During mating,two earthworms come together and exchange sperm. They lie in opposite directions,with the male genital pores of one worm adjacent to the spermathecal pores of the other. Sperm is exchanged and stored in the spermathecae.
$2$. Cocoon Formation: After mating,the clitellar gland cells secrete a mucous and proteinaceous material. This material forms a girdle or ring around the clitellum. As the worm moves backward,this girdle slides forward. As it passes over the female genital pore,it collects eggs,and as it passes over the spermathecal pores,it collects the stored sperm. Finally,the girdle slips off the anterior end of the worm,and its ends seal to form a cocoon. Fertilization and development occur within this cocoon.