(4G) 



fine brownish olive ; scarcely changing either by age or drying. Fructi- 

 fication, a dense stratum of minute angular spores, forming cloud-like 

 spots or sori, immediately under the epidermis of the old fronds. 



This species delights to grow in deep quiet bays, and generally prefers 

 to grow in an erect position, being rarely found attached to the sides of 

 the rocks. In such situations it often forms vast miniature submarine 

 forests, iinder the shelter and shade of which millions of vegetable and 

 animal beings find protection and enjoyment. 



The long flexible fronds bend over by their own weight, they seldom 

 appear above water, except at spring-tides, when the upper part of the 

 stem may be seen with its broad frond gracefully turned over and 

 hanging by its side, or slowly rising and falling Vv-ith the swell, the stems 

 often loaded with bundles of Rhodymenia palmata, Delesseria alata, and 

 other smaller Algae, and the fronds often dotted with multitudes of 

 molluscs of various kinds. 



The stems of this species, under the name of " Cracker-heads," are 

 often eaten by those who live near the sea, the lower part of the stem 

 or even the roots being preferred by some, but it is never exposed for 

 sale along with the other edible species, nor have they, so far as we are 

 aware, been used for food in any part of Scotland for some centuries past. 



We very rarely find this species growing on the perpendicular sides of 

 rocks, yet we have occasionally seen it growing there, and L. stenophylla 

 is sometimes found growing erect, but most freqiiently horizontally. 

 There can never be any difficulty, however, of distinguishing the one 

 from the other, as the smooth, dark-coloured, more or less compressed 

 stems of the one may be known at a glance from the cylindrical, corru- 

 gated, pale brown stems of the other ; and these characters, so far as 

 om- observations go, hold good at every stage of their growth, the 

 smallest specimens having the lower part of the stem at least corru- 

 gated, a very small portion of the summit being generally smooth. The 

 stems of this species are eaten at every age, being rather brittle and 

 cartilaginous, while those of L. stenophylla are only eaten when young, 

 the old stems being tough and coriaceous, and very insipid ; indeed the 

 people on some parts of the coast reject the latter altogether, alleging 

 that it is quite unfit for eating. 



The old stems of L. digitata are occasionally made into handles for 

 knives, &c., being, when diy, almost as hard as horn. 



EXPLANATION OF PLATE CXLVII. 



Fig. l.—Laminaria digitata, young frond, natural size. 

 2. — Section of frond. 

 3. — Spores. Both magnified. 



