LAMl.NARIA DIGITATA. iA9 



qui ne d^couvrent qu'aux plus basses marees d'equinoxe, 

 dans la meme station que le Haligenia bxdbosa; on voit 



721 et722. — Apres avoir decril le mode de fabrication de la soude 

 usit6 par les Orcadiens et qui est exactement semblable aux prece- 

 des employes sur les cutes de Cherbourg, et apres avoir insiste 

 sur les ressources qu'offre tout particulierement le Laminaria 

 digitata, soil pour la fabrication de la soude, soit pour I'amende- 

 ment des terres, M. Clouston continue ainsi : 



« Notwithstanding the importance of this plant, there is none 

 ■which has been more confused with those that are at all allied to 

 it than this; the older botanists describing it under the name 

 Fucus saccharinus and F. phillilis on the one hand, and the F. 

 bulbostis on the other; and even in the recent and excellent works 

 of Turner and Hooker, it is evident that two very distinct plants 

 are described under the name of Laminaria digitata. When adhe- 

 ring to the rock, the two plants are known in Orkney under the 

 names of the tangle and the cuvy, which shall be retained at 

 present, though it must be evident, from the following marks of 

 distinction, that each is entitled to a separate scientific name. 



Root. — The fibres of the root of the cuvy are arranged in longi- 

 tudinal lines or rows, not whorls; while the fibres of the tangle 

 have no order at all. This arrangement of the fibres is particulary 

 evident, as the plant is frequently thrown on shore having all 

 except the stumps worn away by friction. 



Stipes. — The stipes of the cuvy scarcely ever exceeds four or 

 five feet in length, while its circumference near the root is some- 

 limes seven inches. It is so sh/T'asto stand up almost perpendicular 

 two thirds of its height; but droops at the top from the weight of 

 the frond. It is surrounded by a rough bark as thick as paste board, 

 which may be separated from it. Colour, light brown; much 

 infested with parasitical plants, particularly the Ptilota plumosa 

 and Halymenia palmata or dulse. It tapers much towards the top, 

 but retains its round figure till it spreads immediately into the 

 frond. The lower end tastes very salt and is not eatable. The .sti- 

 pes of the tangle, on the contrary, frequently attains the length of 

 eight or ten feet, while its circumference seldom exceeds four 

 inches. It is so flexible as to lie prostrate on the rocks; has a smooth 

 polished surface, and no bark that can be separated, at least casi- 



