A CONTRIBUTION TO OUR KNOWLEDGE OF 
SPLACHNIDIUM 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 220 
MasBeEt LEwIs ROE 
(WITH PLATES XIV—XVIII) 
Introduction 
Splachnidium rugosum Grev. is a monotypic genus of more 
than ordinary interest because investigators have placed it in 
one group or another according as some particular feature seemed 
more worthy of emphasis. The earliest mention of this plant was 
by Linnaeus (9) as Ulva rugosa; a few years later SuHR (18) de- 
scribed it as Dumontia rugosa; and in 1830 GREVILLE (3) founded 
the genus Splachnidium, retaining the specific name already given. 
Most authors have placed it with the Fucaceae, but in 1892 
MITcHELL and WuirttiInc (10) published an account which was 
incorporated in 1895 by Murray (11) in his book. This account 
includes the morphology of both vegetative and reproductive 
tissues. As a result of their investigations, these authors felt 
justified in establishing a new family, making the following state- 
ment (p. 9): “The sum of the characters of Splachnidium so 
expressly excludes it from any existing natural order that there is 
no other course open to us than to establish one for its reception 
under the name of Splachnidiaceae.”” KyELLMAN’s account (6) 
restored it to the Fucaceae; and in 1904 Otrmanns (13) placed 
it with the Ectocarpaceae under the subgroup Encoelieae. 
The material for this investigation was secured by Professor 
Cuartes J. CHAMBERLAIN at Glen Cairn, near Cape Town, South 
Africa, on February 28, 1912. A second collection was made at the 
same place on August 30, 1914, by Miss Eprra STEPHENS of South 
African College, Cape Town, and sent to Professor CHAMBERLAIN. 
_ The work was undertaken with the hope of determining (1) the 
nature of the contents of the reproductive sacs, whether zoospores 
or gametes; and (2) the origin of the so-called “apical cell,” @ 
Botanical Gazette, vol. 62] [400 
