The life history ofPorphyropsis coccineaVar.Dawsoniiin culture

Abstract

Young blades of Porphyropsis coccinea var. dawsonii formed monospores either by the production of a concave wall separating a small monosporangium from a larger mother cell or by the release of entire cell contents. Spores could develop into either filaments or monostromatic disks from which upright blades were subsequently produced. This filamentous stage, hitherto unreported, differs from the Conchocelis phases reported for Bangia and Porphyra in that pit connections and fertile cell rows are lacking. The life history was completed under each illumination condition employed and no evidence for the photoperiodic control of growth and development was obtained.