OBSERVATIONS OX CANADIAN CONIFEE.E. 



27 



coal from the Pittsburg beds, specimens of which I have had an opportunity of exam- 

 ining, I find that in one case the mass is finely laminated and lustrous, with an irregularly 

 conchoidal fracture. The surface layers show numbers of rod-like filaments of variable size, 

 ranging from 0'20 mm. to 1-0 mm. In the second case the specimen was shaly, and exter- 

 nally showed several rods, several fish-teeth, and the macrospore of a Lycopodiaceous plant. 

 The filaments were variable, ranging from 0'20 mm. to 0'65 in diameter, with an average 

 of O'3-l mm. The fracture was conchoidal, black and lustrous. The transection of these 

 rods was round or elliptical. In the first specimen combustion was not free, and upon 

 heating the material rapidly broke up into small fragments. No satisfactory microscopical 

 results could be obtained, either by section or maceration. In the second specimen com- 

 bustion was free, producing a copious smoke. Sections disclosed no internal structure, but 

 showed the transparent rods to l)o imbedded in a black, granular matrix, which has all the 

 appearance of broken down cellular structure; and within it were found a uumljer of small 

 bodies having the aspect of spores, generally grouped together, and of two dimensions. 

 They measured 2 /( and 4-8 /< in diameter. Superficially these rods frequently exhibit 

 markings which take the form of longitudinal striations, or more frequently of narrow trans- 

 verse bands, either separately or combined A\'ith the longitudinal strite. In one particular 

 case the transverse markings were very prominent and eminentlj- suggestive of the annula- 

 tions of certain worms, notably those of Cirratulas grandis. When these transverse lines 

 were less prominent, there was often more or less well-defined reticulation, suggestive of 

 tlie impress of cellular structure. 



!More recently Mr. Gresley has forwarded to me a series of drawings representing these 

 surface markings, and they seem to emphasize the idea of their origin in the impress of 

 surrounding tissue. These drawings are reproduced here. 



From these facts it appears that the coals from the 

 Wyoming, Pittsburg, Illinois and Kootanie beds are all of 

 the same general character, and, although they difter some- 

 what in detail, their origin was undoubtedly the same in 

 each case. 



As already shown,' these rods most probably had their 

 origin in material held in solution. As this solidified by 

 liberation of the volatile solvent, it took the forms and 

 dimensions of the structures in which it was produced or 

 which it had penetrated, and as the solidification continued 

 always from the surface towards the centre of the mass, 

 there arose internal shrinkage fissures, which took the form 

 of variously branching tubes or even of plates. 



In this connection it should be kept in mind that there 

 are known instances of modern coniferous trees which pro- 

 duce resin in very large quantity. In the Fiji islands, the 

 Moluccas and New Zealand Dammara orientalis, D. australis and D. vitiensis or macropkylla, as 

 well as other species, produce enormous quantities of the commercial resin known as dammar 

 or kauri. This material, as it flows from the tree, is thin and viscous, but after a few days 

 of exposure hardens into copal-like lumps, which have been known to obtain a weight 



3 



Bods from Pittsburg coal showing 

 form and markings. 



' " American Geologist," x., 336. 



