Legal questions of the constitutionality of tax on inter-state sales, and the exercise of the power of appointment, will be argued by seniors of the Law School tomorrow and Thursday nights in the semi-finals of this year's Ames Competition between the student law clubs.

The arguments will be held both evenings in Langdell Hall at 8 o'clock and will be open to the public without charge. The decisions will single out as victors over thirty other clubs in a two year competition before student courts, the two ablest senior teams, which will meet for the final arguments in January.

Sitting as Judicial bench for the mock trial tomorrow evening will be Ferdinand Pecora, Judge of the Supreme Court of New York; W. Calvin Chestnut, Federal District Judge for Maryland; and Scott Wilson, Circuit Judge for the First Circuit.

Thursday night the court will include John J. Parker, Circuit Court for the Fourth Circuit; Edwin L. Page, Justice of the Supreme Court of New Hampshire; and Clarence G. Washburn, Judge of the Court of Appeals of Ohio.

The student "counsel" for tomorrow's argument will be, for the Jeremiah Smith Law Club, James N. Ackerman and John R. Covington; for the Pow-wow Club, John L. Burling '34 and William H. Smith.

Thursday night the counsel will be, for the Marshall Club, William Grant and James S. Kemper, Jr.; and for the Powell Club, Thomas J. Davis, Jr. and William L. Fay.