CHAPTER III. CONDITIONAL OBLIGATIONS. SECTION 1434. Obligation, when conditional. 1435. Conditions, kinds of. 1439. Performance, &c., of conditions, when essential. 1441. Impossible or unlawful conditions void. 1442. Conditions involving forfeiture, how construed. § 1434. An obligation is conditional, when the rights or duties of any party thereto depend upon the occurrence of an uncertain event. § 1435. Conditions may be precedent, concurrent, or subsequent. § 1436. A condition precedent is one which is to be performed before some right dependent thereon accrues, or some act dependent thereon is performed. § 1437. Conditions concurrent are those which are mutually dependent, and are to be performed at the same time. 53 Cal. 723. § 1438. A condition subsequent is one referring to a future event, upon the happening of which the obligation becomes no longer binding upon the other party, if he chooses to avail himself of the condition. § 1439. Before any party to an obligation can require another party to perform any act under it, he must fulfil all conditions precedent thereto imposed upon himself; and must be able and offer to fulfil all conditions concurrent so imposed upon him on the like fulfilment by the other party, except as provided by the next section. //. 4. 25. § 1440. If a party to an obligation gives notice to another before the latter is in default, that he will not perform the same upon his part, and does not retract such notice before the time at which performance upon his part is due, such other party is entitled to enforce the obligation without previously performing or offering to perform any conditions upon his part in favor of the former party. § 1441. A condition in a contract, the fulfilment of which is impossible or unlawful, within the meaning of the Article on the Object of Contracts, or which is repugnant to the nature of the interest created by the contract, is void. § 1442. A condition involving a forfeiture must be strictly interpreted against the party for whose benefit it is created. CHAPTER IV. ALTERNATIVE OBLIGATIONS. SECTION 1448. Who has the right of selection. 1449. Right of selection, how lost. 1450. Alternatives indivisible. 1451. Nullity of one or more of alternative obligations. § 1448. If an obligation requires the performance of one of two acts in the alternative, the party required to perform has the right of selection, unless it is otherwise provided by the terms of the obligation. § 1449. If the party having the right of selection between alternative acts does not give notice of his selection to the other party within the time, if any, fixed by the obligation for that purpose, or, if none is so fixed, before the time at which the obligation ought to be performed, the right of selection passes to the other party. § 1450. The party having the right of selection between alternative acts must select one of them in its entirety, and cannot select part of one and part of another without the consent of the other party. § 1451. If one of the alternative acts required by an ob ligation is such as the law will not enforce, or becomes unlawful or impossible of performance, the obligation is to be inter preted as though the other stood alone. TITLE III. TRANSFER OF OBLIGATIONS. SECTION 1457. Burden of obligation not transferable. 1460. Covenants running with land, what. 1461. What covenants run with land. 1462. Same. 1463. Same. 1464. What covenants run with land when assigns are named. 1465. Who are bound by covenants. 1466. Who are not. 1467. Apportionment of covenants. § 1457. The burden of an obligation may be transferred with the consent of the party entitled to its benefit, but not otherwise, except as provided by section 1466. § 1458. A right arising out of an obligation is the property of the person to whom it is due, and may be transferred as such. § 1459. A non-negotiable written contract for the payment of money or personal property may be transferred by indorsement, in like manner with negotiable instruments. Such indorsement shall transfer all the rights of the assignor under the instrument to the assignee, subject to all equities and defences existing in favor of the maker at the time of the indorsement. 55 Cal. 129. § 1460. Certain covenants, contained in grants of estates in real property, are appurtenant to such estates, and pass with them, so as to bind the assigns of the covenantor and to vest in the assigns of the covenantee, in the same manner as if they had personally entered into them. Such covenants are said to run with the land. § 1461. The only covenants which run with the land are those specified in this title, and those which are incidental thereto. § 1462. Every covenant contained in a grant of an estate in real property, which is made for the direct benefit of the property, or some part of it then in existence, runs with the § 1463. The last section includes covenants "of warranty," "for quiet enjoyment," or for further assurance on the part of a grantor, and covenants for the payment of rent, or of taxes or assessments upon the land, on the part of a grantee. § 1464. A covenant for the addition of some new thing to real property, or for the direct benefit of some part of the property not then in existence or annexed thereto, when contained in a grant of an estate in such property, and made by the covenantor expressly for his assigns or to the assigns of the covenantee, runs with land so far only as the assigns thus mentioned are concerned. § 1465. A covenant running with the land binds those only who acquire the whole estate of the covenantor in some part of the property. § 1466. No one, merely by reason of having acquired an estate subject to a covenant running with the land, is liable for a breach of the covenant before he acquired the estate, or after he has parted with it or ceased to enjoy its benefits. § 1467. Where several persons, holding by several titles, are subject to the burden or entitled to the benefit of a covenant running with the land, it must be apportioned among them according to the value of the property subject to it held by them respectively, if such value can be ascertained, and if not, then according to their respective interests in point of quantity. TITLE IV. EXTINCTION OF OBLIGATIONS. CHAPTER I. PERFORMANCE, §§ 1473-1479. II. OFFER OF PERFORMANCE, §§ 1485-1505. III. PREVENTION OF PERFORMANCE OR OFFER, §§ 1511- IV. ACCORD AND SATISFACTION, §§ 1521-1524. VI. RELEASE, §§ 1541-1543. CHAPTER I. PERFORMANCE. SECTION 1473. Obligation extinguished by performance. 1477. Partial performance. 1478. Payment, what. 1479. Application of general performance. § 1473. Full performance of an obligation, by the party whose duty it is to perform it, or by any other person on his behalf, and with his assent, if accepted by the creditor, extinguishes it. § 1474. Performance of an obligation, by one of several persons who are jointly liable under it, extinguishes the liability of all. § 1475. An obligation in favor of several persons is extinguished by performance rendered to any of them, except in the case of a deposit made by owners in common, or in joint ownership, which is regulated by the Title on Deposit. § 1476. If a creditor, or any one of two or more joint creditors, at any time directs the debtor to perform his obligation in a particular manner, the obligation is extinguished by |