The symbiote pouch is a small pouch unique to Jaffa physiology. It is similar to that of a marsupial. The symbiote pouch holds the premature Goa'uld symbiote needed to sustain the Jaffa's immune system. The pouch is made during the prim'ta, when a young Jaffa comes of age and receives his symbiote. The Goa'uld remains there, in incubation, until it matures and is able to take a host. The relationship between a premature symbiote and Jaffa differs from that of a mature Goa'uld, in that the premature symbiote within a Jaffa symbiote pouch cannot exert control over the host. That can only be done when the Goa'uld has matured and is attached to the brain of the host. Even baseline Humans can receive symbiote pouches.