'Hazel' wood was induced experimentally in Pinus halepensis Mill. by parallellongitudinal scratches. Two years after treatment, the growth rings showed indentations where the cambium had been scratched. Tissues formed following wounding had many very large resin ducts in addition to the normalsized ones, irregularly shaped tracheids and ray cells, more rays, spiral orientation and narrower tracheids. We suggest that the wounding disturbed the normal hormonal balance, and that disturbances in hormonal balance probably are the physiological basis for other cases of hazel growth.