﻿38 Canadian Record of Science. 



silicitied and strongly resistant epidermis of the grasses 

 and Equiseti. The formation of tabashir in the hollow 

 joints of certain bamboos might be held to offer a fair 

 basis for comparison, but all analogy fails when it is recalled 

 that the often large masses of silica thus met with are 

 altogether amorphous and deposited as the residuum of the 

 fluids originally present. In the known deposition of 

 silica in plants, there are, in fact, no grounds for 

 comparison, and, from a botanical point of view, there is 

 no way of reaching an adequate explanation of the 

 presence of such rods of silica in charcoal. It is, in fact, 

 quite within the limits of safety to assert that it would be 

 altogether contrary to normal processes of growth for 

 such deposits to occur in living tissues. 



"We are thus confronted with the alternative that the 

 silica must have been taken up by the charcoal itself. It 

 is a well known fact that charcoal often retains all 

 the prominent structural features of the original tissues in 

 a remarkable degree, and it thus becomes possible to see 

 how the casts could so completely represent the structure 

 of the vessels. 



In whatever form the silica entered the coal, the fact 

 that it later appears as complete casts shows that it 

 solidified within the vessels before the latter were 

 destroyed by combustion. 



2nd. The rods have been shown to present a diversity 

 of appearances. They are clear and glass like : opaque 

 through the inclusion of air or of what seem to be 

 particles of unconsumed carbon ; or they again appear — but 

 more particularly in the massive form — of a greenish 

 white color like slag. Collectively, these appearances 

 point to the view that the infiltrated matter must have 

 entered the coal in a molten state, and that it is in reality 

 slag in which the coal was immersed, a conclusion which 

 is greatly strengthened by Prof. Donald's statement that 



