24 Armitagb, Plant Remains in Olivine-Basalt. [^^'^june''^' 



bonized wood, the vegetable organization being still visible in the 

 former. Amongst this black matter a portion of the trunk of a 

 tree appears, in a direction parallel to the side of the vein, and 

 therefore erect, being entire and unbroken for the space of at 

 least six feet. On careful examination of this wood it appears to 

 be fir, which at least it perfectly resembles in its anatomical 

 structure. ... I believe that in all the instances hitherto 

 described, the wood has, as in the present case, been found in a 

 conglomerate or in some other rock, either lying under, or 

 entangled in the basalt, and not in the basalt itself." 



This description is further illustrated by a plate showing the 

 position of the carbonized wood in the conglomerate. 



In a paper by Mr. Cadell (9), printed in 1892, is recorded the 

 discovery of a fossil in basalt at Bo'ness Coalfield, Linlithgowshire, 

 Scotland. He speaks of " the specimen, which is preserved in 

 greenstone." ..." The fossil is part of a Lycopod stem." 

 . . . " With the exception of (a) very thin coating of iron 

 oxide, and perhaps a little carbonaceous matter mixed with it, 

 the original plant in its upper part is entirely replaced by crystal- 

 line calcite." ..." The great interest of the specimen 

 centres in the matrix in which it is preserved. The occurrence of 

 a plant preserved in basalt is perhaps unique." 



Mr. Walcott (10) described, in 1899, an occurrence discovered 

 in a basalt quarry at Footscrav, which is about four miles west of 

 Melbourne. This was a tree that had been pseudamorphously re- 

 placed by basalt. He says: — "The original body (of the tree trunk) 

 had first been entirely removed, leaving a cavity or mould which has 

 been subsequently filled by a molten mass of lava. The cast 

 retains the external appearance of a tree, but is quite devoid of 

 all other similarity." This specimen may be seen in the Mineral- 

 ogical Section of the National Museum, Melbourne. In both 

 this occurrence and that described by Mr. Cadell, pseudomorphs, 

 in the one case, of basalt, and in the other, of calcite, exist in the 

 place of the original material of which the plants consisted, such 

 original material having quite disappeared. 



In connection with a discovery of fossil wood under the famous 

 Sgurr (or Scuir) of Eigg, one of the islands of the Inner Hebrides 

 of Scotland, much controversy has arisen as to the nature of the 

 actual matrix in which the fossil plant remains were found. Some 

 writers seem to think that all of the fossil wood occurs in a breccia 

 or conglomerate under the pitchstone of which the Sgurr is 

 composed ; while others aver that, although the greater part of the 

 wood occurs in that situation, yet some at least is to be found 

 actually in the decayed base of the pitchstone. The statements 

 of two or three of those who have written on the subject may be 

 quoted. 



Mr. Hugh Miller (11), in 1858, thought the pitchstone repre- 

 sented a volcanic flow that overspread beds of Oolitic grits resting 



