Except for certain peculiarities due to the fact that the original contract was under seal, or that it was required to be in writing or to be proved by writing,1 the general rule is that the new contract may abrogate the earlier contract either expressly or by implication. The modification may be by oral contract,2 or it may be implied from the conduct of the parties.3 If a contractor has entered into a contract with the United States, and he requests an extension of time, the conduct of the United States in permitting him to continue without giving a definite answer to such request until after the contract has been performed, and the work has been accepted, is equivalent to an agreement to give a reasonable extension of time.4

3Hughes v. Brennan Construction Co., 24 D. C. App. 90; Sioux City Stock Yards Co. v. Sioux City Packing Co., 110 Ia. 396, 81 N. W. 712; St. Croix Co. v. Seacoast Canning Co., 114 Me. 521, 96 Atl. 1059; Napa Valley Wine Co. v. Daubner, 63 Minn. 112, 65 N. W. 143.

4 Hughes v. Brennan Construction Co., 24 D. C. App. 90.

5 Seech. LXXXI.

6 See ch. LXXXVIII.

1 These peculiarities are discussed in detail in Sec. 2472 et seq.

2 Murray v. Boyd, 165 Ky. 625, 177 S. W. 468; Faust v. Rohr, 167 N. Car.

360, 83.S. E. 622; Wilson v. Maxon, 56 W. Va. 194, 49 S. E. 123.

3 Arkansas. Grider v. Three States Lumber Co., 72 Ark. 190, 79 S. W. 763.

Colorado. Hennessey v. Fleming, 40 Colo. 27, 90 Pac. 77; Princess Amusement Co. v. F. E. Edbrooke Architect Co., 58 Colo. 207, 144 Pac. 893.

Georgia. Bearden Mercantile Co. v. Madison Oil Co., 128 Ga. 695, 58 S. E. 200.

Illinois. Evans v. Howell, 211 111. 85, 71 N. E. 854.

Iowa. Sutton v. Griebel, 118 Ia. 78, 91 N. W. 825; Michigan Stove Co. v. Walker, 150 Ia. 363. 130 N. W. 130.

Kansas. Evans v. Jacobitz, 67 Kan. 249, 72 Pac. 848.

Maine. Hilton v. Hanson, 101 Me. 21, 62 Atl. 797.

The fact that one of the parties to the contract has requested the other party in performing it to render services or to furnish articles which are not required by the contract, may amount to a modification of the original contract, so as to include an agreement for such extras together with a promise to pay therefor.5 If the owner of property has entered into a building contract and he subsequently requires the contractor to perform extra work,6 such as the removal of rubbish from the premises,7 such request operates as an implied promise to pay extra compensation for such extra services. The act of a husband and wife, who have entered into a contract of separation, in living together after such contract has been made, operates as a termination of such contract by mutual consent,8 since a contract for future separation is invalid.9 If a contract, by which A sells certain standing timber to B, provides that the track which B should construct upon the property in removing the timber should become the property of A at the end of the time fixed by the contract, and if A knows and acquiesces in B's conduct in replacing such track with a more permanent structure than the original track, gets in bad condition, and if A acquiesces in B's sale of the iron from such track to C, A's conduct amounts to a modification of the original contract,10 and C has a right to remove such iron.11 A agreed to buy a share in certain property to be purchased. Before completing the purchase he gave notice that he withdrew, and the adversary party secured another subscriber for A's share. This was held to amount to an implied rescission of A's contract by consent.12 If an insurance company issues a policy containing certain grounds of forfeiture when it knows of the existence of one of such grounds, such clause of forfeiture is thereby waived.13 A course of dealing with the agent of an insurance company may waive a provision requiring payment of premiums as a condition precedent to liability.14 A provision in a policy requiring proof of loss to be submitted in a certain time, is waived by the act of the insurance company in agreeing to pay such loss, thereby causing the insured to delay submitting such proofs.15

Massachusetts. Boyden v. Hill, 198 Mass. 477, 85 N. E. 413; Mark v. Stu-art-Howland Co., 226 Mass. 35, 115 N. E. 42

Nebraska. Herpolsheimer v. Christopher, 76 Neb. 352, 107 N. W. 382.

New Jersey. Bird v. J. L. Prescott Co., 89 N. J. L. 591, 99 Atl. 380.

North Carolina. Parns v. McFar-land, 146 N. Oar. 382, 59 S. E. 1011.

Oklahoma. Ahrens v. Ahrens, - Okla. - . 169 Pac. 486.

Vermont. Davenport v. Crowell, 79 Vt. 419, 65 Atl. 557.

4 Noel Construction Co. v. United States, 50 Ct. Cl. 98.

5 Hennessey v. Fleming, 40 Colo. 27, 90 Pac. 77.

See Sec. 1459.

6 Hennessey v. Fleming, 40 Colo. 27, 90 Pac. 77.

7 Hennessey v. Fleming, 40 Colo. 27, 90 Pac. 77.

8 Ahrens v. Ahrens, - Okla. - , 169 Pac. 486.

10 See Sec. 938.

to Grider v. Three States Lumber Co., 72 Ark. 190, 79 S. W. 763.

11 Grider v. Three States Lumber Co., 72 Ark. 190, 79 S. W. 763.

The. question of waiver of provisions in insurance policies is often complicated with questions of the authority of the agent by whom such alleged waiver is made. If he has no authority to waive such provision the insurance company is not bound by his acts.16 Thus under a provision that concurrent insurance should avoid a policy unless the agent indorsed such permission thereon in writing only, the knowledge of such agent that other insurance exists does not waive such provision of the policy.17

12Sutton v. Griebel, 118 Ia. 78, 91 N. W. 825.

13 United States. Continental Life Ins. Co. v. Chamberlain, 132 U. S. 304, 33 L. ed. 341.

Indiana. Glens Falls Ins. Co. v. Michael, 167 Ind. 659, 8 L. R. A. (N.S.) 708, 74 N. E. 964, 79 N. E. 905; German Mutual Ins. Co. v. Niewedde, 11 Ind. App. 624, 39 N. E. 534.

Kentucky. Baldwin v. Ins. Co., 107 Ky. 356, 92 Am. St. Rep. 362, 54 S. W. 13.

Michigan. Crossman v. American Ins. Co., 198 Mich. 304, 164 N. W. 428.

Montana. Wright v. Fire Insurance Co., 12 Mont. 474, 19 L. R. A. 211, 31 Pac. 87.

Nebraska. Hanover Fire Ins. Co. v. Bohn, 48 Neb. 743, 58 Am. St. Rep. 719, 67 X. W. 774; German Ins. Co. v. Sha-der, 1 Neb. (unofficial') 704, 60 L. R. A. 918, 96 N. W. 604.

New York. Hudson v. Glen Falls Ins. Co., 218 N. Y. 133, L. R. A. 1917A, 482, 112 N. E. 728.

Oregon. Arthur v. Ins. Co., 35 Or. 27,

76 Am. St. Rep. 450, 57 Pac. 62. Texas. Aetna Ins. Co. v. Holcomb,

89 Tex. 404, 34 S. W. 915.

Wisconsin. McQuillan v. Life Association, 112 Wis. 065, 88 Am. St. Rep. 986, 56 L. R. A. 233, 87 N. W. 1069, 88 N. W. 925.

14 Phoenix Mutual Life Ins. Co. v Doster, 106 U. S. 30, 27 L. ed. 65; Run-beck v. Farmers' & Bankers' Ins. Co., 96 Kan. 186, 150 Pac. 586; Baldwin v. Ins. Co., 107 Ky. 356, 92 Am. St. Rep. .362, 54 S. W. 13.

15 Thompson v. Ins. Co., 136 U. S. 287, 34 L. ed. 408; Kenton Ins. Co. v. Wigginton, 89 Ky. 330, 7 L. R. A. 81, 12 S. W. 668; Flynn v. Orient Ins. Co.,

77 N. H. 431, 92 Atl. 737; Rheims v. Standard Fire Ins. Co., 39 W. Va. 672, 20 S. E. 670.

16 Northern Assurance Co. v. Building Association. 183 U. S. 308, 46 L. ed. 213; Ferdcnando v. Milwaukee Mechanics' Ins. Co., 81 Wash. 244, 142 Pac. 693.