EFFECTIVE DATE.

SEC. 125. EFFECTIVE DATE. The amendments made by this part shall be applicable only with respect to taxable years beginning after March 31, 1951, and to taxable years beginning on January 1, 1951, and ending on December 31, 1951, except that the amendments made to sections 207, 362, and 421 of the Internal Revenue Code shall be applicable to taxable years beginning after December 31, 1950, and ending after March 31, 1951. In the case of an insurance company subject to the tax imposed by section 207, the provisions of section 26 (b) of such code applicable to the calendar year 1951 shall be applicable to a taxable year beginning after December 31, 1950, and before April 1, 1951, and ending after March 31, 1951. For treatment of taxable years (other than the calendar year 1951) beginning before April 1, 1951, and ending after March 31, 1951, see section 131.