In an exchange qualifying for Sec. 351 IRC tax-free treatment, Roberta receives 100 shares of White Corporation stock plus a contingent right to receive another 25 shares. The shares are contingent upon the valuation of patent contributed by Roberta. Because the patent license is pending, the patent cannot be valued for several months. Prepare a memorandum for your tax manager explaining whether the contingent shares are considered "stock" for purposes of Section 351 IRC and what tax consequences ensue from Roberta's receipt of the actual and contingent shares of stock