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

Abstract

Ectocarpus siliculosuswas named by Dillwyn (5) in 1809 and described by him in theBritish Confervœof that date. It was included by Harvey (9) in thePhycologia Britannicaunder the same name, but according to Hauck (10) in theMeeresalgen Deutschlands und Oesterreichsthe 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 ofE. confervoides(Roth) Le Jol. If this view be correct, the plant should beE. 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 speciessiliculosus. 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 fromE. 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 theCatalogue of the British Marine AlgœasE. siliculosusKütz.