KONGL. SV. VET. AKADEMIENS HANDLINGAK. BAND. 20. N:0 5. 231 



Total length of the niga. Lengtii of the stipe. Length of the lamina. Greatest breadth. 



310 



70 



240 



50 cm. 



307 _ 



57 .. 



250 



66 



285 _... 



35 



250 



56 



241 _.... 



31 



210 



50 



236 



26 



210 



51 



220 



25 



195 



52 



216 



16 



200 



128 



48 



183 



55 



28 



With regard to stnicture f. grandifolia ditfers also from the before-mentioned 

 forms by having miich 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, soinetimes rare. In one 

 specimen I have fonnd a few ruga^ 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 L. saccharina or some other species 

 dififerent from it, is a question I must leave undecided at present. Just as f. <:jrandi- 

 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 Bohuslän which is distinguished by its short stipe, and thin almost membra- 

 naceous lamina, that is linear with rounded base and wants ruga3. 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 elongated 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 rugaj. In structure it accords 

 nearly with the preceding form, showing the same differences as this from f. linearis 

 and f. oblonga. The lacunai muciferas 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. Ägardhii even more than f. yrandifolia does. It is 

 distinguished from it by the same characteristics as f. grandifolia. It is this form la- 



