Civ. Code, § 731.05

(a) All receipts of money or other property paid or delivered as rent of realty or hire of personalty, or interest on money loaned, or interest on or the rental or use value of property wrongfully withheld or tortiously damaged or otherwise in return for the use of principal, shall be deemed income unless otherwise expressly provided in this chapter. Dividends on corporate shares, payable in stock or otherwise, shall be deemed income except as provided in Section 731.07.

(b) All receipts of money or other property paid or delivered as the consideration for the sale or other transfer, not a leasing or letting, of property forming a part of principal, or as a repayment of loans, or in liquidation of the assets of a corporation, or as the proceeds of property taken on eminent domain proceedings where separate awards to tenant and remainderman are not made, or as proceeds of insurance upon property forming a part of the principal except where such insurance has been issued for the benefit of either tenant or remainderman alone, or otherwise as a refund or replacement or change in form of principal, shall be deemed principal unless otherwise expressly provided in this chapter. Any profit or loss resulting upon any change in form of principal shall inure to or fall upon principal, except in the case of property referred to and defined by Section 731.14, in which case the provisions of Section 731.14 shall govern.

(c) All income, after payment of expenses properly chargeable to it, shall be paid and delivered to the tenant or retained by him if already in his possession or held for accumulation where legally so directed by the terms of the transaction by which the principal was established; while the principal shall be held for ultimate distribution as determined by the terms of the transaction by which it was established or by law, except in the case of property referred to and defined by Section 731.14, in which case the provisions of Section 731.14 shall govern.