Describe the structure of the reproductive system of an earthworm with a diagram.

(N/A) $\rightarrow$ Earthworms are hermaphrodites,meaning both testes and ovaries are present in the same individual.
$\rightarrow$ Two pairs of testes are present in the $10^{th}$ and $11^{th}$ segments.
$\rightarrow$ Their vasa deferentia run up to the $18^{th}$ segment,where they join the prostatic duct.
$\rightarrow$ Two pairs of accessory glands are present,one pair each in the $17^{th}$ and $19^{th}$ segments.
$\rightarrow$ The common prostatic and spermatic duct opens to the exterior by a pair of male genital pores on the ventrolateral side of the $18^{th}$ segment.
$\rightarrow$ Four pairs of spermathecae are located in the $6^{th}-9^{th}$ segments (one pair in each segment). They receive and store spermatozoa during copulation.
$\rightarrow$ One pair of ovaries is attached at the intersegmental septum of the $12^{th}$ and $13^{th}$ segments.
$\rightarrow$ Ovarian funnels are present beneath the ovaries,which continue into the oviducts,join together,and open on the ventral side as a single median female genital pore on the $14^{th}$ segment.
$\rightarrow$ Mating: $A$ mutual exchange of sperm occurs between two worms during mating. They mate by juxtaposing opposite gonadal openings.
$\rightarrow$ The male genital pores of one worm come in contact with the spermathecal pores of another earthworm.
$\rightarrow$ In this situation,due to the release of sperm,sperm cells enter the spermathecae of the companion animal.
$\rightarrow$ After the exchange of sperm cells,the companion animals separate.
$\rightarrow$ Formation of Cocoon: After some time,the glands of the clitellum secrete a white,girdle-like structure.
$\rightarrow$ Due to contraction,the girdle/tube slowly moves towards the anterior end.
$\rightarrow$ As the girdle moves towards the anterior end and passes the spermathecal region,the sperm cells stored in the spermathecae enter it.
$\rightarrow$ Now,this tube contains the egg cells of the same animal,the sperm cells of the companion animal,and nutrient fluid.
$\rightarrow$ Both ends of the tube/girdle that come out of the body are closed. This closed tube is the cocoon. Fertilization takes place within it,and the egg cells result in a zygote.
$\rightarrow$ After about $3$ weeks,each cocoon produces two to twenty baby earthworms.
$\rightarrow$ The development of the earthworm is direct,meaning no larval stage occurs during development.