Abstract

Wavy grain in Grewia tiliifolia was found to be associated with patches of abnormal parenchymatous (callus) tissue. Insect injury was shown to induce the formation of such wound healing tissue which was subsequently overgrown. This tissue caused deviation of grain around it. Its surface irregularities led to the formation of grooves and ridges on the tangential surface. During recovery of normal wood structure in successive layers some abnormalities in the morphology of rays were observed. These were found to be the transitional stages which ultimately gave rise to normal rays