the generic Characler of Uha, &c. 57 



the principal frond, after being once divided near the bifc, con- 

 tinues fimplc for three feet, when it becomes dichotomous, and 

 thefe branches then continue undivided to the end. The whole 

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

 comprefTed at their origin* and again above and below the angles of 

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

 terminate obtufely. In Jubilance it differs from all other known 

 marine Alga ; 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 deflitute of any outer (kin; in confequence of which it 

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

 uneven appearance. It may perhaps-be objected, that this fpecics 

 does not fufficiently agree with the nat. char, the fru&ification 

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

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

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

 epidermis the exterior granulations mull neceffarily appear to be 

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

 pofed, that the outer part containing the granulations is paralitica!, 

 and formed upon i'omefucus or other plant belonging to the A/g,c; 

 but, befides that no paralite 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 difleclin;*- 

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

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

 The central part is green, the reft of the internal lubftance whitifh ; 

 of the furface, one half, which isfuppofedto be what in floating, or 

 when left by the tide, is uppermoit, is green, the other part dirty white. 

 Vol. III. I From 



