Pollen Analysis Circular maintain contact with one another and maintain publication lists that had, until then, been published by Gunnar Erdtman as "Literature on Pollen Statistics and Related Topics". The first issue of the "Pollen Analysis Circular" was dated May 5, 1943 and published by Paul B. Sears (Oberlin College). Subsequent issues were generally edited by Sears, sometimes in cooperation with L.R. Wilson. In January 1945, the "Pollen Analysis Circular" was renamed the "Pollen and Spore Circular" to more accurately reflect its scope. After 1954, the Circular was incorporated into the "Micropaleontologist", soon renamed "Micropaleontology", published by the American Museum of Natural History.
Medullary ray (botany) also known as vascular rays or pith rays. In this context, the term refers to radial sheets or ribbons extending vertically through the tree across and perpendicular to the growth rings. Also called pith rays or wood rays, these formations of primarily parenchyma cells allow the radial transport of sap and are essential in the process of tylosis. In quartersawn material, where the wood is cut into boards with the growth rings roughly perpendicular to the face of the board, the medullary rays often produce beautiful figure such as silver grain, medullary spots, pith flecks, etc. Medullary ray (botany) Medullary