The space between the spikes in the male accessory gland had inclusion. Many rough endoplasmic reticulum, mitochondrium and lysosome existed in the secretory cell of gland lumen.

The sericin globule was formed in Golgi complex of the middle silk gland cell and the sericin was released into the gland lumen by the similar way of fibroin fibers.

Compared with the thyroid gland of grey mullet, the endostyle of amphioxus is primitive. It is an open groove and has lots of cillia adjacent to the pharynx lumen.