{ 62 )• 



harsh and less lubricous, cylindrical, and traversed by an internal tube 

 occupying about two-thirds of the diameter, and divided at a distance of 

 about two diameters by membranous diaphragms, not indicated by any 

 external constriction or swelling. Structure consisting of two strata of 

 cells ; the inner large, oblong, and cylindrical, the outer minute, gradually 

 smaller to the surface, where they are moniliform, all more or less 

 arranged in longitudinal filiform series. Substance cartilaginous, rather 

 flaccid when young, and closely adherent to paper, by means of its 

 covering of lubricous hair-like filaments ; less so when old, and these 

 have become abraded. Colour, a dark olive-green, almost black when 

 dry. Fructification : minute obconical spores, attached by a long pedicel 

 to the sm-face of the frond, and enclosed in a wide pellucid limbvis, 

 forming a dense stratum on the outer surface of the frond, and " mixed 

 with numerous narrow, elliptical, transversely striate bodies, which may 

 be antheridia." 



This curious plant is said to be abundant throughout all the north 

 temperate zone, both in the Atlantic and Pacific, and even to be foimd 

 in Brazil {Phyc. Brit.), so that it and allied species are perhaps equally 

 abundant in the sovithern hemisphere. 



It is found in more or less abundance on all the British shores, 

 but in particular in quiet bays and deep pools at and beyond low- 

 water mark, varying in length according to the depth at high-water, 

 beyond which it never grows, whilst at low-water it may be often 

 seen spreading on the surface for a distance of several feet, the lower 

 part standing erect in dense patches, or bending gracefidly in the 

 swell, thus forming a singularly ciurious and beautiful submarine 

 grove, through which the fingered and finny tribes gambol in fancied 

 secmity. 



In autumn the tufts often become more or less matted and twisted 

 together, forming rope-like masses, often of great length and thickness, 

 and then become torn from then' base, and are thrown on the beach in 

 large masses. It is an autiunn plant, and seldom makes its appeai'ance 

 till the summer has considerably advanced. 



The variety /3 tomentosa is a very beautifid one, and may be occa- 

 sionally met with in the same pool with the normal form, but is much 

 less common. 



Sir W. Hooker mentions another variety {BiHt. Fl. vol. ii. p. 276), 

 /3 thrix, with " frond very slender, almost capillary, two to four inches 

 in length ; " this we have not seen. 



The " elliptical bodies " noticed above are plentifully scattered among 

 the obconical spores, and are described by Professor Harvey as " anthe- 

 ridia^' and by Captain Carmichael as a diff"erent kind of spores. 



