CONFERVA FENESTRALIS. 



C. filamentis repeinibus minutillimis, tenuiffimis, ramofis, centrifugis : 

 ramis plerumque divaricatis. 



C. feneftralis, Roth, Fl. Germ. III. pars I. Cat. Bot. II. p. i6r. III. 

 p. 180. 



On Glafs. 



I OBSERVED that feveral of the pieces of glafs on which I preferve my Con- 

 ferva;, and which had lain in a damp place were covered over with a very minute 

 mucor-like down, which on examination in the microfcope I found to accord fo 

 nearly with the defcription of Roth's C. feneftralis, that I feel no hefitation in 

 publifhing it as that fpecies. The filaments are of a light grey, inclining to afli 

 color, and fo minute that the glafs on which it grows has rather the appear- 

 ance of being foiled than covered by vegetation ; it adheres to the dried con- 

 fervas, or fome minute fubftance which may moftly be obferved about the 

 roots ; from this as a centre numerous filaments iflue in all directions ; they 

 are ufually from about two to four lines in length, and when they meet with 

 any proper fubftance ftrike root, and throw out other filaments in the fame 

 way. The branches are numerous, and generally divaricate, but the mode of 

 ramification is very irregular, fome of the branches being alternate, fome op- 

 pofite, and three or four are not unfrequently difpofed without interruption 

 on the fame fide. Diflepiments may be occafionally diftinguifhed, dividing the 

 filaments into joints, of which the length is generally about thrice greater than 

 the diameter. The fructification is unknown, but may probably confift in 

 fome granules, which are often obfervable on the branches. In drying C. 

 feneftralis undergoes no change. The drawing was made with the higheft 

 power of a compound microfcope; the extremely fmall fize of the filaments 

 rendering the plant almoft invifible to the naked eye, and confequently pre- 

 cluding the poffibility of figuring it in its natural ftate. 

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