114 DR. Е. BORGESEN ON FUCUS SPIRALIS, LINNÉ. 
Having first copied the diagnoses of this species in *Systema Nature, 
ed. 13, and * Species Plantarum’ ed. 2, p. 1627, Lightfoot gives the following 
description :—* It has the whole habit of the F., vesiculosus, except that, so far 
as we have seen, it is destitute of air-bladders, The stalk or rib is naked at 
the base, being made so by the violence of the waves, but we never observed 
it channelled, as Linnæus mentions. The branches of the leaf are very apt 
to be twisted spirally in their growth, so as to be expanded with difficulty ; 
and their edges, though naturally entire, are often torn or jagged by the rocks 
and waves even to the middle rib, appearing asif cut into lanceolate segments. 
The seminal vesicles grow in pairs at the extremities of the seements, thick, 
obtuse, and generally bifid.” 
It seems to me that this description is so inclusive and striking, that we 
are doing the author an injustice if we have any doubt as to what plant he 
speaks of. 
As to Oeder’s figure in ‘Flora Danica? (vol. ii. fase. 5, tab. 286), the 
oldest existing figure of this species, so far as I know, published as early as 
1766, I willingly admit that it is not particularly good. But nevertheless I 
decidedly maintain that there ean be no question as to its being Fucus 
spiralis, L. The specimen used was badly prepared and is highly * canalicu- 
latus? (comp. Linnés description in ‘Systema Nature; edit. 12). It has 
apparently a vesiele, indeed several small ones are figured in some copies, 
there being a great difference in the reproduction of the various copies. In 
one copy that we have in the library of the Botanical Garden, Copenhagen, 
there are besides the larger “vesicle” in the middle of the plant, drawn on 
the left side of the branch, at a little distance from the midrib, and rather far 
from its apex, also two small ones, but these are placed in such peculiar parts 
of the thallus that it is quite clear that they are not real vesicles; they are 
moreover quite absent from my own copy of * Flora Danica’ As to the large 
“vesicle,” it is in both the copies at. the Library, drawn in. agreement with 
the receptacles, viz. : with the surface dotted all over; the position would be 
a peculiar one in which to find а receptacle, but, judging from the dotted 
surface, it was not intended for a vesicle. In my own copy the vesicle-like 
body is not dotted, but its outline is rather indistinetly sketehed, so that it 
сап scarcely be considered as other than a eurviug of the thallus whieh the 
painter has been at pains to represent. Dy the way, considering my figure 
(fig. 1, p. 107) a little eloser, it struck me that here also. on the upper side 
of the lower branch, to the left of the tipure, a folding of the thallus is 
drawn in such a way that it greatly resembles a vesicle. 
At the same time it is possible for {veus spiralis to have vesicles, though this 
would apparently be infrequent. In the herbarium of the Botanical Museum, 
Copenhagen, a specimen, collected at Haugesund, on the west coast of Norway, 
by Dr. Rosenvinge, has an oval vesicle about ТІ em. long at about $ em. 
