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On the Melanism or Abnormal Colouring of Ferns. 

 By Edward Newman. 



1 HAVE not seen, as far as I recollect, any comments on the striking 

 and often beautiful colouring to which the fronds of ferns are liable. 

 In some instances the veins assume a tint approaching jet black ; in 

 others they are of the most exquisite purple, the leafy portion of the 

 frond remaining of a vivid green : to this description of melanism our 

 British Lastraea recurva and the exotic Cyatheaj are peculiarly liable. 

 A second phase of the property exhibits the leafy portions of a dull 

 purple, the veins retaining the normal green hue : our British 

 Cystopteris fragilis affords frequent examples of this. In a third 

 phase the leafy portions assume a resplendent purple, or glittering 

 bronzed appearance, the veins partially partaking of the same 

 character : beautiful examples of this are exhibited by our common 

 Polystichum aculeatum. 



It has frequently struck me that the truthful discrimination of 

 species might be occasionally retarded by the presence of this 

 character in a hastily gathered frond of an exotic species, so completely 

 does it alter the appearance of the fern : and I therefore thought I 

 might be adding my mite to the general stock of knowledge if I could 

 show how so marked a deviation from normal character is occasioned. 

 With this view I this year watched my ferns very narrowly, and during 

 the usual period of their expanding not an instance of melanism 

 occurred : I however happened to procure some roots of Cystopteris, 

 the fronds of which had been so injured in transit that I thought it 

 best to cut them off, and to plant the roots without fronds : I watered 

 the spot night and morning, and the plants being full of vigour, new 

 fronds were unrolled and rapidly assumed a normal size and appear- 

 ance : I should say that the spot on which they grew enjoyed one hour 

 of the midday sun. One morning, circumstances occurred to delay 

 the morning watering until near noon ; it was a brilliant day ; the air 

 still, and the sky cloudless ; after the lapse of a few minutes the sun 

 was shining on the young fronds of Cystopteris still dripping with 

 moisture : the evavoration was most rapid, and the vapour might be 

 seen curling up over the bricks among which the roots had been 

 planted. On the following morning the young fronds of Cystopteris, 

 together with those of a Polystichum which had partaken of the sun 

 and water, had become purple, they looked as though died in log- 

 wood. Thus the melanism was produced by natural agents although 

 one of them artificially applied. In ten days both the ferns had 



