the genetic Chara^er of Uha, &e. 57 



tlic principal frond, after being once divided near the bafe, con- 

 tinues fimple for three feet, when it becomes dichotomons, and 

 thefe branches then continue undivided to the end. Tiie whole 

 plant is nearly round and filiform, except that the branches are 

 comprefled at their origin, and again above and below the angles of 

 their dichotomy. The ends of the branches are attenuated, and 

 terminate obtufely. In fubftance it differs from all other known 

 marine y^Igce : the central part is folid and cartilaginous, but at the 

 fame time fomewhat gelatinous ; this is every where furrounded and 

 covered with a fpongy mafs filled with minute granulations, and 

 entirely deftitute of any outer fkin ; in confequcnce of which it 

 retains water like a fponge, and the whole furface has a rough and 

 uneven appearance. It may perhaps be objedled, that this fpecies 

 does not fuflSciently agree with the nat. char, the frudification 

 appearing entirely naked : but although it has that appearance, it 

 is in reality all imbedded in the fpongy fubftance of which the 

 greater part of the frond is compofed, but from the want of an 

 epidermis the exterior granulations muft neceflarily appear to be 

 fituated on the furface, and not beneath it. It might alfo be fup- 

 pofed, that the outer part containing the granulations is parafiticaj, 

 and formed upon iomefucus or other plant belonging to the^/gie; 

 but, befides that no parafite is ever known fo entirely to cover the 

 living plant on which it grows, that no part by which it might be 

 difcovered is left naked, the fpongy matter containing the granu- 

 lations fo abfolutely proceeds from, and forms a part of, the more 

 folid centre, that with the utmoft care and attention in difledling 

 it has not been poffible abfolutely to feparate them, and no doubt 

 can poflibly remain of their forming one entire and perfect planr. 

 The central part is green, the reft of the internal fubftance whitifti ; 

 of the furface, one half, which is fuppofed to be what in floating, or 

 when left bythe tide, is uppermoft, is green,the other part dirty white. 

 Vol. III. I From 



