330 DR. SARAH M. BAKER AND MISS М. Н. BOHLING ON 
intermediate between those of the var. Mackaii and the typical upright, short- 
stalked receptacles of A. nodosum. The reproductive organs of the var. 
scorpioides, like those of most other marsh Fucoids, are not functional, and 
the oogonia do not undergo any divisions. 
The var. minor of A. nodosum is also found embedded in the marsh soil, 
though sometimes attached to pebbles below, in the Hurst Castle salt 
marshes, Hants (see Cotton in Morris, 1914, р. 192). It does not, at 
present, show the morphological peculiarities associated with the salt- 
marsh varieties of this species; but is worth keeping under observation, 
as it may, in time, give rise to the var. scorpioides. 
THe Marsa Кост. 
(a) The Marsh Representative of Fucus spiralis, L. 
The dwarf variety of Fucus spiralis, characteristic of exposed situations on 
a rocky coast, is frequently found, attached to the subsoil with a definite dise, 
on the mud cliffs or channel banks of marshes. It has been amply described 
and discussed by Bórgesen (1909, p. 109) and Sauvageau (1908, рр. 91-97), 
and previously reported from the salt marsh by Cotton (1912, р. 82). It 
shows no peculiarities on the salt marsh, reproduction being normal, and the 
habit being identical with specimens from the rock preserved in the British 
Museum and Kew herbaria. 
(b) The Marsh Forms of Fucus vesiculosus, L. 
Under this heading we have to discuss all the other marsh Fuci which have 
been described from the British Isles. The range of form among them is 
enormous ; but they all have in common :—(1) embedded or unattached 
habit ; (2) reproduction by vegetative budding ; (3) terminal position of 
receptacles, where present; (4) numerous and prominent cryptostomata, 
chiefly marginal in position. 
The nomenclature is chaotic ; but this seems to be largely due to the fact 
that systematists have ignored the ecological distribution of the forms, For 
this reason there has been a continual confusion between the series, occurring 
here and on the French coasts, upon salt marshes, and the parallel, but not 
identical, series which occurs in the loose-lying formations of the Baltic (see 
par. entitled “The Baltic Fuci," р. 338). 
The first question is the parentage of the marsh ci, and, as specimens 
from different localities are never identical in habit, it was necessary to study 
the Fuci from as many marshes as possible. 
