In entire harmony with the Constitution, the law says expressly what the Committee shall do. Besides the general charge and superintendence, they shall "determine the _number_ and _qualifications_ of the scholars to be admitted into the school,"--thus, according to a familiar rule of interpretation, excluding other powers: _Mentio unius est exclusio alterius._ The power to determine the "number" is easily executed, and admits of no question. The power to determine the "qualifications," though less simple, must be restricted to age, sex, and fitness, moral and intellectual. The fact that a child is black, or that he is white, cannot of itself be a qualification or a disqualification. Not to the skin can we look for the criterion of fitness. It is sometimes pretended, that the Committee, in the exercise of their power, are intrusted with a discretion, under which they may distribute, assign, and classify all children belonging to the schools _according to their best judgment_, making, if they think proper, a discrimination of race or color. Without questioning that they are intrusted with a discretion, it is outrageous to suppose that their discretion can go to this extent. The Committee can have no discretion which is not in harmony with the Constitution and Laws. Surely they cannot, in any mere discretion, nullify a sacred and dear-bought principle of Human Plights expressly guarantied by the Constitution. * * * * * REGULATIONS OF COMMITTEE MUST BE REASONABLE. Still further,--and here I approach a more technical view of the subject,--it is an admitted principle, that the regulations and by-laws of municipal corporations must be _reasonable_, or they are inoperative and void. This has been recognized by the Supreme Court in two different cases,--_Commonwealth_ v. _Worcester_, (3 Pick. R., 462,) and in Vandine's case (6 Pick. R., 187). In another case, _City of Boston_ v. _Shaw_, (1 Met. R., 130,) it was decided that a by-law of Boston, prescribing a particular form of contribution toward the expenses of making the common sewers, was void for inequality and unreasonableness. Assuming that this principle is applicable to the School Committee, their regulations and by-laws must be _reasonable_. Their discretion must be exercised in a reasonable manner. And this is not what the Committee or any other body of men think reasonable, but what is reasonable in the eye of the Law. It must be _legally reasonable_. It must be approved by the _reason_ of the Law.