KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 20. N:0 5. 231 
Total length of the alga. Length of the stipe. Length of the lamina. Greatest breadth. 
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With regard to structure f. grandifolia differs also from the before-mentioned 
forms by having much wider and more thin-walled elements. This is especially the 
case with the collenchyme and the adjoining parenchyme of the stipe and with the 
parenchyme of the lamina. The central layer of the stipe is composed of thinner cells 
with more swollen membranes. 
The pits of the lamina are sometimes very numerous, sometimes rare. In one 
specimen I have found a few ruge in the middle part of the lamina. 
In the lamina three parts are distinguishable: the middle part which is smooth 
or almost smooth, the intermediate part with many depressions, and the marginal part 
which is thin, wavy, with few depressions. 
L. saccharina f. latissima. This is not the preceding form at a different age, as 
one might be inclined to suppose. For I have examined young specimens of both the 
forms that plainly showed the same shape of the lamina as in older individuals. But 
though I have not seen any transitions between them, they resemble each other in so 
many respects that they are probably to be considered as less strongly differentiated 
forms of the same species. Whether this is really LZ. saccharina or some other species 
different from it, is a question I must leave undecided at present. Just as f. grandi- 
folia corresponds to the southern L. saccharina f. membranacea and replaces it in the 
North, f. latissima may be regarded as a northern form corresponding to a L. saccharina 
existing at Bohuslén which is distinguished by its short stipe, and thin almost membra- 
naceous lamina, that is linear with rounded base and wants rug. From f. grandifolia 
f. latissima is distinguished almost exclusively by the shape of the lamina. This is in 
younger individuals almost linear with rounded base, or clongated linear-ovate. When 
older, it increases considerably in breadth and becomes broadly elliptical with ovato-cordate 
or cordate base. The surface is sometimes smooth, sometimes covered more or less 
densely with pits. I have seen one specimen with low ruge. In structure it accords 
nearly with the preceding form, showing the same differences as this from f. /énear/s 
and f. oblonga. The lacune mucifere in the lamina are sometimes scarce, sometimes 
numerous, always large, confined in a greater or less extent of their periphery by cells 
that are smaller and of another shape than the other cells of the parenchyme. The 
form in question resembles L. Agardhii even more than f. grandifolia does. It is 
distinguished from it by the same characteristics as f. grandifolia. It is this form /a- 
