Ray Tracheids in Abies

1. Ray tracheids, marginal, interspersed, and elongated, were observed in association with wounds in A. amabilis and A. concolor. 2. They were also observed in uninjured material of A. homolepis and A. Veitchii. 3. Their usual position was in contact with a series of degenerated cells on one hand and a group of parenchyma on the other. 4. Transitions from ray tracheids to parenchyma were common, some elements having both bordered and simple pits, and others pits with borders of various sizes. 5. All the evidence points to ray tracheids being present in the ancestors of Abies and absent today by reduction.