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DB. W. NTLA^'BEa ON A.BTHONI.V MELASPEE^fELL.V. 341 



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otes on Dr. W. 

 mella, Bv Wil 



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Translated and 



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[R^ad June 21, 1866.] 



Dr. LiNDSAT asserts (Linn. Soc. Journ. vol. ix. p. 281) that I 

 regard Lecidea lutea as a fungus ; but such has never been my 

 opinion, and never have I expressed such an opinion. In my 

 ' Lich, Scandin.* p. 192, which Dr, Lindsay quotes, I describe (as 

 elsewhere in my other writings) this beautiful lichen as a lichen, 

 Without saying a single word which could lead any one to sup- 

 pose that there was the least doubt that this was anything else 

 than a true lichen. On the same page I speak solely of Stictis 

 radiata and pallida^ Pers., as being properly referable to the 

 lungi, notwithstanding a certain character of the gelatina hyme- 

 nea by which they approach the Zeeidece, I believe that Dr. 

 Lindsay equally deceives himself in wishing to attribute " several 

 forms of spermogone and pycnide " to the same lichen, p. 273. 

 ■Wo lichen has ever presented to mj observation more than one 

 smgle kind of spermogonium ; and the pycnides are rare, and are 

 i^ot constantly present as the spermogonia; but that which with- 

 out doubt has led Dr. Lindsay into error is this, that parasites 

 are frequent on the thalli of lichens, and also that it is not rare 

 to see a thallus, especially a pulverulent one, covering another 

 thallus, in such a manner that the two lichens appear to con- 

 stitute only a single lichen, having three or four organs of repro- 

 duction {appareils reproducteiirs). In like manner we often 

 s^e a lichen covering a fungus (e.g. Ilysterium pulicare). The 

 pycnides, which are often regarded as the fructifications of 



lichens, are, however, very frequently only the fructifications of 

 fungi. 



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I wish also to be permitted to rectify an error of Dr. Lindsay 

 on page 283. He believes that the thecce contain the lichenlne; 

 this is not the case. The reaction in these organs is external 

 and superficial. When their summits become blue with iodine, 

 and of a deeper blue than their other portions, this is not the 

 result of a change of colour tcitJdn the cavity of the thecae, but in 

 the thin layer on i\\eir exterior HuxfsiCQ. Moreover that which in 

 chemistry has been named lichenme^ is yevy^ little known to 

 chemists, and is probably nothing else but the amorphous 

 starch passing more or less into dextrine; and this occaaions the 



