Pelvetia fastigiata

Abstract

The cell walls of the pith and cortex of Pelvetia fastigiata are perforated, and protoplasmic connections are evident. Walls of pith cells are formed of many lamellae. Hair pits exist, although not in great numbers. Con-ceptacles are found below the fruiting tips; the lower conceptacles have no sex organs. There are often 4 eggs in each oogonium instead of 2, as usually reported. Division is not transverse but longitudinal. Binucleate eggs occur. Abortive nuclei are extruded between the 2 or 4 eggs, not in the equator and outside, as in the European species of Pelvetia. Oogonia are stalked. Antheridia are stalked like oogonia, only seldom being borne on paraphyses. Antheridia have 2 wails. Author''s summary.