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are distinctly transverse sections, and show the ends of organisms. 
But this is not the case with a block of coal, which may be likened to 
a pack of cards, the four sides in question having a similar appearance, 
and, so far as structure is concerned, having each an equal title to be 
called a longitudinal section. Where, then, is the transverse section 
of coal, and where are the yellow rings ? 
“ Hitherto our attention has been directed to the sides of the block, 
let us now examine the top and bottom, or horizontal surfaces—there 
the rings are found, and being there, cannot be the ends of the sup- 
posed tubes, nor have any relation to them, seeing that their longitu- 
dinal direction is that of the surface now under examination. 
“T have drawn three sections, as if seen in one perspective view, in 
their natural position. The stripes on one side are seen to extend far 
into the side at right angles, showing themselves to be plates of trans- 
parent matter lying betwixt the carbonaceous layers. | 
“The grinding and polishing process is very instructive. On the 
sides of the blocks many series of rings may be ground off without 
much alteration on the appearance of the striae, while in reducing the 
horizontal surface the transparent parts are constantly changing their 
form. The first evidence of transparency which presents itself is a 
deep blood-red spot, beautifully soft at the edges; grind a little 
farther, and it assumes the appearance recognized as the resinoid cell; 
a little more grinding, and the spore-case makes its appearance ; still 
grind on, the process will be found to be as fertile of form as the frost 
is on the window-pane, or the burning embers of the fire to a musing 
fancy ; and when the section is reduced to the last degree of thinness, 
the shallowest of all peep through. These are the yellow rings, with 
their dark centres, on which I shall venture a few observations sugges- 
tive of their origin. 
“A painting of a transverse section, executed by Dr. Adams, of 
Glasgow, and shown by Professor Bennett to the Royal Society, re- 
presents the rings as if they were all in the level, and of a uniform 
colour. ‘This has no doubt been in some measure the cause of their 
having been mistaken for the ends of tubes. Nature shows them dif- | 
ferent. Some are distinct and bright yellow, while thin as the section 
is when they come into view, others are still obscured by a layer of 
dark matter, and have a bister-brown colour. Mr. Quekett admits this 
to be the case; it is therefore a matter of astonishment that, with such 
a high and well-earned reputation for acute observation, he, at the 
same time, describes them as transverse sections of thick-walled cells 
or woody fibre. 
