Sharpnack, Senior Judge
In response to the State’s assertion of waiver, Bigger argues in his reply brief that the statute providing for the defense of abandonment does not require a formal pleading or notice of the defense. See Ind. Code § 35-41-3-10 (1977). Although we find no statutory or case law requirement that the defense of abandonment be formally pleaded, our review of this case discloses that the jury was not even aware that they could consider this defense. Bigger did nothing to reveal his intent to rely on the defense of abandonment in this case. He did not file any pleading asserting the defense of abandonment, he did not cross-examine the State’s witnesses regarding evidence of his alleged abandonment, he did not mention his alleged abandonment in closing argument or any other time at trial, and he did not tender any final instructions on the defense of abandonment and the court gave none.
We deem necessary the assertion of the defense in some manner. Were it otherwise, the trier of fact would not know to consider the defense in its deliberations of a defendant’s guilt, as was the case at Bigger’s trial. . . . .
MAY, J., and CRONE, J., concur.