Labrum - a cover which may be loosely referred to as the upper lip. Mandibles - hard, powerful cutting jaws. Maxillae - 'pincers' which are less powerful than the mandibles. They are used to steady and manipulate the food. Labium - the lower cover, often referred to as the lower lip.
The President, as head of the federal executive branch, is ultimately in charge of enforcing the immigration laws of the United States. In turn, he must make discretionary decisions about whether and when to prosecute immigration law violators through deportation and other sanctions.
The Immigration Act, also known as the Hart-Celler Act, was signed by President Lyndon B. Johnson 50 years ago on Oct. 3 and took full effect three years later.