Since bankruptcy proceedings contemplate a sale of the debtor's assets, the importance of knowing what the trustee may sell is at once obvious. One must, however, go further and inquire as to the rights of purchasers from the trustee. This question assumes importance to the trustee, since it determines what he may sell, and is also important to the purchaser, since it determines what he may buy. The answer determines the efficiency of our bankruptcy machinery. In this comment we propose to consider one phase of this general question: May the trustee assign his right to set aside a fraudulent conveyance made by the debtor?