from the same point. These contain, in some individuals, antheridia, affixed 

 to branching threads ; in others, globose spores, which at length separate 

 into four sporules. Substance exceedingly tough and leathery. Colour a 

 dull, olive-green ; which becomes black in drying. 



This is the largest of the British species of the restricted genus 

 Fucus, and by far the toughest and most rigid. Its substance is 

 thicker and denser than that of any of the others, and its frequently 

 pinnated habit, and remarkably large vesicles, added to the ribless 

 frond, afford strong marks of distinction. When in fructification, 

 the great abundance of the clear yellow receptacles contrasts 

 agreeably with the colour of the other parts of the frond. Like 

 most other submersed plants this varies in luxuriance according 

 to the depth at which it grows : specimens near high-water mark 

 being short and bushy, often exceedingly crowded in branches, 

 and thickly covered with fruit ; while those produced near ordi- 

 nary low -water are drawn out to a great length, with more 

 distant branches. The older authors founded varieties, which 

 are scarcely worth noticing, on these differences. 



Fucus nodosus is almost always more or less infested with 

 Folysiphonia fastigiata, which forms globose tufts of a rich 

 brown colour on various parts of its fronds. This parasite is not 

 confined to the present species, however, but may often be seen 

 on old stumps of F. vesiculosus, to which it generally attaches 

 itself near the root only. 



F. nodosus is one of those largely used in the manufacture of Kelp, 

 which it yields in considerable quantities. Oystermen sometimes 

 employ it to cover their oysters, though F. serratus is more gene- 

 rally employed for that purpose. In Scotland this plant is called 

 Sea- Whistles ; and boys make whistles of the larger air-vessels, 

 according to Lightfoot, by cutting them across near one end. 



Fig. 1. Fucus nodosus ; portion of a frond — of the natural size. 2. Segment 

 of a receptacle : — slightly magnified,. 3. A spore : — highly magnified. 



