A written contract not required to be in writing or to bo proved by writing is valid though not signed if the parties intend it to take effect without signing.1 Thus if one party signs it and the other acquiesces therein,2 as by acting under it3 such contract is binding, both on the party signing,4 since the liability of the adversary party is a consideration for his liability, and on the party who does not sign.5 Thus a bill of lading,6 or a railroad ticket,7 or a pass8 containing contractual provisions is valid though unsigned. Thus a treasurer who assents to a bond purporting to be given by him for money received, but does not sign it, is liable thereon.9 So, while a guardian's bond which is assented to by the guardian, but not signed by him, is not good as a statutory bond it may be good as a Common Law bond.10 A gave an order for a mowing machine to B's agent, X. The order was signed by A., and provided for reserving to A "the full benefit of the warranty endorsed hereon." On the back of the order was a printed warranty with vendor's signature printed thereunder, and the blanks unfilled. It was held that such reference made the warranty a part of the written contract, and accordingly the vendor's acceptance of the order made the warranty as binding upon him as if he had signed it.11 If it is the understanding of the parties that a contract is not to be binding upon the person named therein until he signs it, his omission or refusal to sign it will prevent it from being his obligation.12 The question of the necessity of signature by the parties to a written contract is complicated with the doctrine of mutuality. Written agreements are made which impose obligations on one party, provided the other person will do certain things, but do not, expressly or by implication, require such other person to do such things. Such written agreement is in the nature of a written offer. If the party upon whom obligation is not imposed performs the acts upon which the obligation of the other party was conditioned, this amounts to an acceptance, and the contract is in legal effect a written contract.13 Thus, a contract signed by a lumber company to pay a certain amount for water if a water company would extend its mains to the lumber yard, is binding on the lumber company as a written contract if the water company extends the mains in accordance with the condition of such written agreement.14 A person upon whom obligations are not imposed by such writing, may subsequently accept such written offer orally and agree to perform the conditions therein indicated. This contract is valid as between the parties, but as part of it consists of oral terms, it is for technical purposes treated as an oral contract.15 The part of it which is in writing falls within the parol evidence rule, however, and can not be contradicted by extrinsic evidence any more than if the entire contract were in writing.

1 Hinote v. Brigman, - Fla-. -; 33 So. 303; Sellers v. Greer, 172 Ill. 549; 40 L. R. A. 589; 50 N. E. 246; Farmer v. Gregory, 78 Ky. 475; David Bradley v. Bower (Neb.), 99 N. W. 490.

2Ross v. Parks, 93 Ala. 153; 30 Am. St. Rep. 47; 11 L. R. A. 148; 8 So. 368; Vassault v. Edwards, 43 Cal. 465; Sellers v. Greer, 172 Ill. 549; 40 L. R. A. 589; 50 N. E. 246; Vogel v. Pekoe, 157 Ill. 339; 30 L. R. A. 491; 42 N. E. 386; Memory v. Niepert, 131 Ill. 623; 23 N. E. 431; Ames v. Moir, 130 Ill. 582; 22 N. E. 535; Plumb v. Campbell, 129 Ill. 101; 18 N. E. 790; Harlan v. Gas Co., 133 Ind. 323; 32 N. E. 930; Midland Ry. Co. v. Fisher, 125 Ind. 19; 21 Am. St. Rep. 189; 8 L. R. A. 604; 24 N. E. 756; New Iberia Riee-Milling Co. v. Romero, 105 La. 439; 29 So. 876; Western Ry. Corp. v. Babeoek, 6 Met. (Mass.) 356; Bacon v. Daniels, 37 O. S. 279; Grove v. Hodges, 55 Pa. St. 504; Swisshelm v. Laundry, 95 Pa. St. 367; Sylvester v. Born, 132 Pa. St. 467; 19 Atl. 337; McPherson v. Fargo, 10 S. D. 611; 66 Am. St. Rep. 723; 74 N. W. 1057; Lowber v. Connit, 36 Wis. 176; Vilas v. Dickinson, 13 Wis. 488. "Where a party accepts and adopts a written contract, even though it is not signed by him, he shall be deemed to have assented to its terms and conditions, and to be bound by them." Forthman v. Deters, 206 Ill. 159; 69 N. E. 97.

3 Sellers v. Greer, 172 Ill. 549; 40 L. R. A. 589; 50 N. E. 246; McKee v. Cowles, 161 Ill. 201; 43 N. E. 785; Vogel v. Pekoe, 157 Ill. 339; 30 L. R. A. 491; 42 N. E. 386.

4Whatley v. Reese, 128 Ala. 500; 29 So. 606; Lavenson v. Wise, 131 Cal. 369; 63 Pac. 622.

5 Harts v. Emery, 184 Ill. 560; 56 N. E. 865; Edwards v. Gildemeister, 61 Kan. 141; 59 Pac. 259; American, etc., Co. v. Walker, 87 Mo. App. 503; Carnegie Natural Gas Co. v. Philadelphia Co., 158 Pa. St. 317; 27 Atl. 951; Slayden v. Stone, 19 Tex. Civ. App. 618; 47 S. W. 747.

6 Field v. Ry., 71 Ill. 458; Anchor Line v. Dater, 68 Ill. 369; Adams Express Co. v. Carnahan, 29 Ind. App. 606; 63 N. E. 245; 64 N. E. 647; Gaines v. Union Transportation Co., 28 O. S. 418; Ryan v. Ry., 65 Tex. 13; 57 Am. Rep. 589.

7 Walker v. Price, 62 Kan. 327; 84 Am. St. Rep. 392; 62 Pac. 1001; Danger-field v. Ry., 62 Kan. 85; 61 Pac. 405; Rahilly v. R. R., 66 Minn. 153; 68 N. W. 853; Gregory v. R. R., 10 Neb. 250; 14 N. W. 1025; Abram v. Ry., 83 Tex. 61; 18 S. W. 321; Drummond v. R. R., 7 Utah 118; 25 Pac. 733.

8Quimby v. R. R., 150 Mass. 365; 5 L. R. A. 841; 23 N. E. 205.

9 Senour v. Maschinat (Ky.), 31 S. W. 481.

10 Painter v. Mauldin, 119 Ala. 88; 72 Am. St. Rep. 902; 24 So. 769.

11Grieb v. Cole, 60 Mich. 397; 1

Am. St. Rep. 533; 27 N. W. 579.

12 Meyer v. Labau, 51 La. Ann. 1726; 26 So. 463.

13 Plumb v. Campbell, 129 Ill. 101; 18 N. E. 790.