ilAElNE BOTANY. 17 



was seen no more till May, when preparations being made 

 for recommencing the stone beacon, it was found covered with 

 large sea- weeds; specimens of the Fucus nodosus, the largest 

 of British Algoe, measured six feet in length, and some even 

 exhibited capsules filled with ripening fruit ! and, true to 

 their native habitats, sea-tangles, with their cylindrical and 

 solid stems, and fine clear olive fronds, had also taken root 

 on the smooth and herbless portion of the rock. 



Five species of fuci are recognized as belonging to the 

 British coasts, among which the F. canaliculatus and 

 F. nodosus are best known ; the one affecting rocky shores 

 between high- water mark and half- tide level, and extending 

 in its geographic range along the Atlantic coasts of Europe 

 and North America, but which, unlike most of its con- 

 gener, rarely covers wide spaces of rock, preferring to 

 grow in scattered tufts or places where, at the recess of 

 tide, the water rapidly drains off, evidently for the sake of 

 exposure to the atmosphere during a considerable period 

 daily; the other, similar in its ocean site to the canalicula- 

 tus, is seen on submarine rocks and large boulder-stones 

 from high-water mark to high -tide level. In both, their 

 olive hue designates that they belong to the series melano- 

 sperma — a colour which increases in depth as we approach 

 the tropics, where it reaches the maximum of species, 

 though not of individuals. 



Marine botanists, who desire to acquaint themselves with 

 the structure of these singular productions, should obtain a 

 branch of the F. nodosus or F. canaliculatus, and having 

 well soaked it in water or diluted muriatic acid, cut a thin 

 longitudinal slice, and examine it with a high magnifier, by 

 the aid of which they will readily discover that the whole 

 consists of four distinct parts. The central portion, corre- 

 sponding to the pith of plants, occupies a third of the 

 diameter, and is composed of parallel fibres pressed together 

 —or rather, of numerous cells forming one complete mass. 

 Outside appears a less dense layer, of a paler hue, which 



