This is an action for the conversion of 684.9 bushels of wheat which were stolen from the plaintiff and sold and delivered by the thieves to the defendant, whose manager purchased the grain without knowing that it was stolen. The theft and sale took place during the last part of December, 1932, and the first part of January, 1933, the delivery being made by one Moe. On May 14, 1934, the defendant delivered to plaintiff's attorney a statement of grain that had been hauled by Moe, being the grain which is involved in this action. On September 5, 1934, the plaintiff served upon the defendant a demand to settle for the grain "by making restitution of the grain above described, or grain of like kind and quantity or of paying therefor at the current market price" with which demand the defendant refused to comply. The plaintiff promptly thereafter instituted this action and demanded judgment of the defendant for the value of the wheat as of the date of the demand. The wheat was worth about thirty cents a bushel when it was delivered to the elevator, and $1.03 a bushel when the demand was made. The trial court instructed the jury in effect that if it found that the defendant had converted the plaintiff's wheat that it should determine the value thereof on the date or dates of the purchase by the defendant, and that such value would represent the damages to which the plaintiff is entitled. The plaintiff contends that this is error and that the damage to which he is entitled should be measured by the value of the wheat as of the date of demand.