346 DR. SARAH М. BAKER AND MISS M. Н. BOHLING ON 
In the case of the dwarf Fucus ceranoides, apparently the original 
inoculation is by means of fertilised oogonia from the attached plants in 
the neighbourhood. These become fixed below to the roots or rhizomes of 
Phanerogams ; but if the latter happen to be ephemeral, the anchorage is 
withdrawn after a season, and the Fucus, remaining embedded, continues 
to reproduce itself vegetatively, till, finally, all trace of attachment is lost. 
One dwarf plant of F. ceranoides was found which had a definite attachment 
dise, but was entirely unattached and embedded (fig. 9 A). 
It seems probable that in other cases the marsh forms have arisen by one 
or other of these methods. Certain experiments were set up оп the Samphire 
Marsh at Blakeney Point (for topography see Oliver, Journ. of Ecology, 
1915, p. 13) to test the behaviour of detached fragments of Fuci under 
marsh conditions. А series of ten squares, one foot across, were carefully 
cleared of all alge, and, in each, five pieces of the thallus of Fucus 
vesiculosus from selected rock-plants of characteristic habit, with vesicles 
and dicecious receptacles and showing no spirality, were pinned down, 
covered with netting, and marked. A similar series was made with Fucus 
spiralis plants. The plants were set out on August 20, 1913. On July 10, 
1914, the area was again visited. The tide had evidently scoured the marsh 
considerably ; but of the twenty groups of plantings, five groups of F. spiralis 
and three of F. vesiculosus were left. 
All the specimens of F. spiralis showed normal fruiting and no vegetative 
sprouting. Only one of the F. vesiculosus specimens was fruiting, and all 
were sprouting vigorously from the midrib. Drawings of some of the 
specimens are shown in figs. 12 & 13 (рр. 359 & 360). They were removed 
from the planting because the area was being infected by the ordinary 
v. volubilis coming in with the tide, so that, if the disintegration of the 
original planted fragments were continued much longer, it would be im- 
possible to identify the specimens. The experiments show that the rock 
Е. vesiculosus does tend to sprout vegetatively from small fragments of the 
thallus which may become embedded in the marsh, and probably after one or 
two vegetative generations the characteristic marsh form would be produced. 
It is interesting that 7. spiralis, under these conditions, continues its normal 
course undisturbed ; this possibly explains why it produces no distinct 
variety. Ап experiment in which it was attempted to induce the marsh 
ariety to recur to the habit of F. vesiculosus, by attaching it to a post in 
the channel, was not successful. 
PROPOSED NOMENCLATURE. 
In view of this probable mode of origin of the marsh varieties, we do not 
consider that any of them merit the rank of distinct species. They are rather 
to be regarded as “еса, a name proposed by Clements (1905, р. 148) to 
