Dr. 

 a 



B y s 



like a co>.fcrva, confiftinff of threads, nor of any perceptible 

 do«-ny matter, but merely ofatlun green lanvna. L.,nia:us 

 i„ his Flora Lapponnica, puMilhed thirteen years af.evaards, 

 notices a green iarinaceous Bylfus intermingled with water, 

 which Dillenius.inhisIIilloria Mulconim.qnotes as a.ynonym 

 of hi>ir.cenpapcrByirns,obferving that this plant alio at i:rll 

 confiilsi.fa powdery matterwhich afterwards unites iif.lf into a 

 membranaceous fd,ftance,and wh.n dry becomes white; it is 

 the aq.aiic membranaceous Bydus of tiie Flora Lappoiuoa, 

 vhicl. Linna;-..s himfelf in the Species Plantarum makes a 

 variety of B. flos aqux. Weir, in his Cryptogamia, alfcrts 

 that It is not a real plant, but only unorganiied vegetable 

 matter, produced by the diffolution of putretied p ants. L 

 Withering, on the other hand, believed that it will prove 

 conferva ; for obferving a pond in the ftate of flowering, as the 

 country people term it.he examined fome of the water, but tl.e 

 pirfcles floating in it were fo minute, that even with the al- 

 fillance of a very good mitrofcope he could not fatisfy liim- 

 fclf as to their figure or llrufture. Two or three weeks 

 later in the fpring, he found threads not jointed nor braiichLd, 

 filher ftra-ght or coiled up like a cork-lcrcw. Some of tins 

 water kept m a glaD jar, after two or three weeks more, let 

 its conteiits fuhfide, and then it began to appear 1 ke a con- 

 ferva. The threads foon became much larger and affumed 

 a jo-ntcd appearance. La Marck defcribes it fr-im adual 

 obfervaiion as confiiling of (liort, feathered, extremely tine 

 threads, forming a foft green cruft on the fui face of the 

 water. -;- B. canrellata Linn. " Threads exactly and uni- 

 verfally latticed." Ledcin. Micro, tab. 72. Found in frefli 

 A.ll waters, fvvimmiug like a kind of mucor or mould of a 

 ydlowilh green colour. i,.V>. phofphorca. Linn. "Downy, 

 o! a violet colour, and growing on rotten wood." Dill. tab. i. 

 fig. 6. Conlillin r at tiril of very fine fiiort upright down ; 

 afterwards prelTed'clofe to the wood, cloathiiig it like a thin 

 membrane or crull, taking a deeper violet colour. 5. B. 

 iiiktiKa Linn. " Filamentou? ; green: filaments branched." 

 Dill. tab. I. fig. 14. Found on trees, rocks, and the lur- 

 face of the ground in fhudy phtces, which it covers with a 

 very fine fhort filky down, like velvet, of a beautiful green 

 colour. 6. B. aurea Linn. " Filar.ents fimple or branched, 

 clofely malted together, powdery, orange-coloured." Dr. 

 Smith, Dill. tab. 1. fig. 16. Eng. Bot. ill. Fibres very 

 fine, thick-fet, crcft. Found on calcareous rocks and banks, 

 particularly in Derbyfiiire, and fometimes on damp limeftone 

 buildings. ' It often nmforn-ily covers a fpace of many inches 

 in diameter, and looks like a fine p'ece of orange-coloured 

 cloth or velvet, but the furface is fometimes more tulted and 

 broken, and it frcqu-ntly grows in a llracrgling manner, fcat- 

 tered over moffes. It life? its beauti'ul goklen colour in 

 five or fix weeks after it is gathered, and then becoinee of a 

 permanent grccnilh grey. Dr. Smith. 7. B. n'l^ra Find. 

 " Filiimeits branched, matted, powdery, black." Dr. Smith. 

 Dili. 1. 18. Eng. Bot. 70 !. Fiift fent to Dillenuis by Dr. 

 Riciiardfon from the well riding of Yorkihire. It has fiiice 

 been often found on Ihady overhanging rocks in the atpir.e 

 pans of England, Scotlan ', and Wales. It forms patches 

 of various fizes, perfectly black, and may eafiiy be fcraped 

 from the ftone. W;:en g-rthcred, it llrongly refenibles a 

 piece ot felt fcraped from a hat, both in texture and colour. It 

 confi'.ls of a mat of firic, fo^t, but ela'.tic, branched fiiam.nts, 

 .often covered with an equally bl.iek, f loty powder, which is 

 probably the feed, thou^ih it has not been obkrvcdto be pro. 

 duccd at any particular ftrafon exclufively. Dr. Smith. 8.B. 

 purpurea, Lijfir.foo: ; (Rubra Huds. 2d. eo.) " Filaments 

 cr-.ct, fimp!: or brancheii, p trplifh." Dr. Smith. Eng. Bot. 

 19a. Fila.nents Uarccly longer than the brtadth of a hair, 

 ikick-fet, ill broad nnilorm patches. When much moillened 



B Y S 



thcfe filaments become clotted together in cluftcrs, and in ' 



that moill ilate exhale a kind of f^veet fceiit, agreeing iu thi, 

 refpeCt with the BylTus lolithus of Linnaeus, which is how- 

 ever really a cru'.laceous lichen. Dr. Smith. Found by the 

 Rev. Hugh Davies on the micaceous rocks of Anglefea, and 

 by Mr. i.ightfoot on the bafe of Abbot Mackinnon's 

 tomb in Ycomb-kill. 9. B. fnl-ua Hudfon. " Filaments 

 branched, tawny." Dill. tab. i . fig. 17. Filaments longer, 

 more rigid and more loofely difpofcd than thcfe- of B. .Tiuei, 

 It retains its colour when dry. On putrid wood. lu. B. 

 barhala Huds. (B. aurar.t'iuca La Murck, fui-va Vv'.th.) 

 " Filaments upright, branched, bundled, with a.mual inter- 

 ruptions, tawny, with fmooth, Iwellcd, deeper-coloured 

 tips." Dr. Smith. Dill. tab. I. fig. ly. With. Bot. Ar. 

 tab. iS. fig. 5. Eng. Bot. 701. It forms perenn-al, thick, 

 tawny-coloured tufts, from one to two inch.es high. The 

 growth of each year is marked by a fwelling and a daiker 

 col 'Ur in each principal filament or fttP.i. Young piaiits 

 confitt of a fi.pple filament, regularly and btsutiUi'iy fea- 

 thered at the funimit. In fine fpecimens fent by the ri_;ht 

 honriurable Lady Elizabeth N'oel to Dr. Withcrin;; and Dr. 

 Smith, the fwelled tips were rem^irkably confuicuous. and, 

 as her ladyfhip vvith great probability iuppofed, contained 

 the fruftification. Thefe tips are fmooth, femi-traiifpirent, 

 and of a rich laff on colour. In Dr. Withering s fpecimens, 

 when examined in the microfcope, they were oblervtd to be 

 filled with granules, and to be h-fpid with brillk-fhiped 

 tubes, pointing upwards. In Dr. Smith's Iprcimens, which 

 he conJeCf nres were in a lels advanced I'ate, they had not the 

 fume appearance. On moift rotten wood. II. B. candiJst 

 Huds. " Filaments much branched : branches fafciculated, 

 white." Dill, in Ray's Syn. tab. 23. as it grew on an old 

 beam in a cellar. D'll. Hill. tab. i. A. on an oak leaf; B. on 

 the Hal! rotten fole of an 'Id flioe. From a biondilh, muci- 

 laginous, villous bafe, fpiiig various flender branches, fpread- 

 ing more in breadth than in height, ckgantly divided and 

 fnbdivided,and ending iometimes in numerous capillary fibres, 

 but generally in furfaces a little expanded witliout any de- 

 terminate number or figure. Subilancc pure white, li'. id, or 

 yellowifli, prefied clofe to the fubflance on which it ijrows. 

 Dill. 12. 3. cryp/nrum Linn. "Capillary, perennial, afh- 

 colourcd, adhcruig llrong to the rock on which it grows." 

 Dill. I. 20. Filaments very tender, fott, grcenilh a(h- 

 coloured, an inch long, loofely dilpofed, fo firmly attached 

 as to be fcarcely pulled off by the fingers. Linn. Filaments 

 fimple, dull white, brittle, diverging in a croiided manner 

 fiom a centre, an inch and half long, and the thicknefs of a 

 human ha'r. Dill. 



BYSSUS, or Byssum, a fine fort of thready matter 

 produced in Ind a, Egypt, and about Elis in Achaia, of 

 which the richdl apparel was anc-.ently made, efpecially 

 that wore by the pricfls both Jewilh and Egyptian. 



In reality, the ancituts feein to have applied the name 

 indifferently to any kind of n, alter th.Tt wa» Ipun and wove 

 finer than woo! : fo that it is probable thrrc were divers forts 

 of byfT'is. It is certain, that Arillotie gave the name 

 bylfus to the hair or filken threads of the pinna marina ; 

 whether it were on account of its relenblance to the byfTus 

 or which cLths were made, or whether it were that this 

 was the true bylfus itfelf. What countenances this latter 

 opinion is, that the byffns of the pinna manna may be fpun, 

 and coiifequently there is little doubt but tliHt in ages when 

 filk was fcarce, it might be ufed in the cloaths of great men. 

 Add, that this by flfus, though grofsly fpun, appears much 

 finer and more beautiful than wool, anxi comes no; much 

 (lloit of filk. Stockings and other fuch maniifaciurcs are 

 ftill made of it, which would be more valuable if filk were 



lef» 



