**ABOMASUM**, or **ABOMASIUS**, names of the fourth stomach of ruminating animals. The first stomach is called **venter**, the second **reticulum**, the third **omasus**, and the fourth **abomasus**. The third stomach, omasus, is endowed with the singular quality of curdling milk. But the truth is, the stomachs of almost all animals, whether they ruminate or not, will produce the same effect, though not perhaps in an equal degree, as the stomachs of calves or lambs. See **MILK**, **RUNNET**.