The maaser of animals is drawn from within the area that a grazing animal [is left to] range. How far is a grazing animal [left to] range? Sixteen mil. [If] there were thirty-two mil between them, they do not combine. If he had [animals] between them, they must be brought together and be tithed in the middle. R’ Meir says: The Jordan separates [them] in regard to the maaser of animals.