28. The periodicity, regularity and recurrence of a receipt has been considered to be a hallmark of its character as income in accordance with the ordinary concepts and usages of mankind. Likewise, the need to distinguish capital and income for trust purposes and other purposes has focused attention on the difference between the right to receive future income and the receipt of that income, a difference which has given rise to the analogical difference between the fruit and the tree (see Shepherd v. Federal Commissioner of Taxation [1965] HCA 70; (1965) 113 CLR 385, at p 396). Both the "ordinary usage meaning" of income and the "flow" concept of income derived from trust law have been criticized - see Professor Parsons, "Income Taxation: An Institution in Decay?" (The 1986 Wilfred Fullagar Memorial Lecture). For present purposes it is sufficient for us to say, without necessarily agreeing with these criticisms, that, valuable though these considerations may be in categorizing receipts as income or capital in conventional situations, their significance is diminished when the receipt in question is generated in the course of carrying on a business, especially if it should transpire that the receipt is generated as a profit component of a profit-making scheme. If the profit be made in the course of carrying on a business that in itself is a fact of telling significance. It does not detract from its significance that the particular transaction is unusual or extraordinary, judged by reference to the transactions in which the taxpayer usually engages, if it be entered into in the course of carrying on the taxpayer's business. And, if it appears that there is a specific profit-making scheme, it is pointless to say that it is unusual or extraordinary in the sense discussed. Of course it may be that a transaction is extraordinary, judged by reference to the course of carrying on the profit-making business, in which event the extraordinary character of the transaction may reveal that any gain resulting from it is capital, not income.