368 Botanical 



this genus had been multiplied without due attention to nature. In 

 particular, he believed that Blelia Jlorida, B. verecunda, B. Shep- 

 herdii, and he feared even B. patula, must be considered mere mo- 

 difications of the same species. Specimens upon which this opinion 

 was formed were exhibited. Dr Graham also exhibited a specimen 

 in flower of Philodendron crassinervium. This plant had been in- 

 troduced into the Botanical Garden, from Brazil, by Captain Graham 

 sixteen years ago ; but though it had several times developed flower 

 buds, the spatha had never till this season fully expanded, probably 

 owing to the command of heat having been heretofore inadequate. 

 > — W. H. Campbell, Sec. 



Glass eroded by a Lichen. — " Several pieces of glass were lately 

 brought to me by a glazier in this city, taken from the old windows 

 of an ancient church in the vicinity ; some of these had the appear- 

 ance of being worm-eaten. Struck with the singularity of this, I 

 immediately commenced an investigation of the circumstance, that 

 I might ascertain by what agency this corrosion had been induced. 

 Upon making a minute examination, I found it was caused by the 

 instrumentality of a cryptogam ic plant, I believe of the lichen species. 

 The first indication of the plant was a greenish pulverulent mould 

 on the surface of the glass ; in this substance some light-coloured 

 brown dots appear ; these enlarge, and form cup-like substances of 

 a slightly violet tinge ; these plants increase, and become fully de- 

 veloped. The glass is gradually acted upon, being first a little 

 roughened and indented ; afterwards small cavities, some even pene- 

 trating a considerable distance into the substance of the glass, are 

 formed. 



" Not having read or heard of any plant having hitherto been dis- 

 covered capable of decomposing and growing on and in the substance 

 of glass, I thought it right to make a public communication of the 

 fact through the medium of the pages of your valuable periodical, 

 leaving it to other and abler naturalists and philosophers to disclose 

 the kind of agency, whether chemical or galvanical, by which this 

 singular decomposition of glass is effected. 



" The glaziers of this city inform me, that glass similarly acted 

 upon may be met with in the cathedral and old church windows." 

 Thomas Hickes, Gloucester, April 25, 1837, in Med. Gazette for 

 May 6. 



Musci Angusiani, or Dried Specimens of the Mosses of Angus 

 or Forfarshire. — This is the title of a work projected by Mr Wil- 

 liam Gardiner, Jun. of Dundee, of which a prospectus has been 



