the excretory system performs excretion
evacuating is excreting. kidney is excretory_organ. urinating is not excreting. excretory_organ is not internal_organ. excretory_organ is internal_organ. animal_excreting is not excreting. evacuating is not excreting. animal_excreting is excreting. kidney is not excretory_organ. urinating is excreting.