XV.—Studies in the Ectocarpaceæ. II. The Life-history and Cytology of Ectocarpus siliculosus, Dillw

Abstract

Ectocarpus siliculosus was named by Dillwyn (5) in 1809 and described by him in the British Confervœ of that date. It was included by Harvey (9) in the Phycologia Britannica under the same name, but according to Hauck (10) in the Meeresalgen Deutschlands und Oesterreichs the specific name should be attributed to Kützing (21), though Hauck himself, following Kjellman (12), is of the opinion that the plant should be regarded as a variety of E. confervoides (Roth) Le Jol. If this view be correct, the plant should be E. confervoides (Roth) Le Jol var. siliculosus (Dillwyn); but in a paper entitled “Beiträge zur Kenntnis einiger Ectocarpus-Arten der Kieler Föhrde” Kuckuck (15) discusses the validity of the species siliculosus. He emphasises certain important features, notably the size and shape of plurilocular sporangia and the frequent presence of a vegetative filament as a prolongation of the sporangium, and considers them to be characteristics clearly distinguishing this plant from E. confervoides (Roth), from which such features are lacking. Batters (1) evidently agrees with Kuckuck in the integrity of the species, but attributes the naming of it to Kützing. The plant therefore appears in the Catalogue of the British Marine Algœ as E. siliculosus Kütz.