Sec. 80. (I) Mistake by drawee as to genuineness of body of instrument or of signature of drawer or indorser. Sec. 81. Same: Why is restitution denied where drawer's signature is forged ? Sec. 82. (1) The conclusive presumption theory. Sec. 83. (2) The negligence theory. Sec. 84. (3) The equal equities theory. Sec. 85. (4) The change of position theory. Sec. 86. (5) The theory that there is no mistake as to drawer's duty to holder. Sec. 87. (6) The theory that the rule is one of policy. Sec. 88. (7) The rule criticized. Sec. 89. (II) Mistake by payor for honor as to genuineness of drawer's signature. Sec. 90. (III) Mistake as to genuineness of payor's signature. Sec. 91. (IV) Mistake as to genuineness of bill of lading attached to draft. Sec. 92. (V) Effect of negligence.