BROWN SEAWEEDS OF THE SALT MARSH. 287 
were further investigated, and a whole series of forms was found, ranging 
from 3 or 4 em. in length and 1 mm. in breadth to the above dimensions. 
Usually the upper levels were occupied by small or narrow varieties, but the 
formation was often mixed. The plants were both with and without vesicles. 
Receptacles were also found on a few of the large specimens. The different 
forms approached F. lutarius and F. vesiculosus respectively in habit. 
A certain number of plants were found with a broad and much crinkled 
thallus (text-fig. 7), which were so distinct in form as to be included under 
a separate variety. Тһе length was about 16-20 em. and breadth about 
15 mm. 
The very tiny Fucus (text-fig. 5, B) found in the Salicornia region of the 
marsh at Blakeney seems very similar in habit to the smallest varieties of 
F. volubilis found at Mersea. It grows in large patches, which might all 
have been produced by the growth of one individual. Tt is possible, however, 
as it occupies a different zone from the other Fucus, that it may be derived 
from a different species; and hence corresponds with the French form, 
Е. lutarius. Its receptacles have not been found. It bears no vesicles. 
The Affinities of the Fucus.—The Fucus, like the Pelvetia, reproduces almost 
entirely by vegetative budding, the buds being produced on the embedded 
part of the thallus, which rots away later, leaving the young shoots to occupy 
its place. A small number of receptacles were found on some of the largest 
Blakeney specimens. Turner, in his description of plants found near Wells, 
Norfolk, mentions the occasional occurrence of receptacles, but does not 
describe them in detail. Of the receptacles examined four were male and 
the rest female. The paraphyses do not project at all from the mouth of 
the conceptacles (Pl. 9. figs. 5 & 6). Та shape the receptacles are either 
short and round or long and narrow and almost pointed (text-fig. 8); they 
are either inflated with mucilage, or the interior is filled with air and a 
confused tangle of hyphe. They are simple or bifid, but always strictly 
terminal. The antheridia seemed to be represented merely by swellings on 
the short branched hyphe (Pl. 9. fig. 5). The oogonia were remarkably 
small and usually undivided ; а few occasional ones were found which had 
divided once, and were arranged like a Pelvetia oogonium, and a few in 
which they had divided a second time ; a section through such an oogonium 
is shown in Pl. 9. fig. 6 at а. ОЁ course, the limited supply of material 
| makes the results more doubtful; but it appears as though the oogonia were 
abortive or not fully developed, which Sauvageau has found to be always the 
case among the very numerous examples of the French F. lutarius he has 
examined. | 
The English species is thus different from the French F. lutarius in several 
most important points. The paraphyses of the French species project very 
considerably from the ostioles of the conceptacles, and, among hundreds of 
