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dication of fossil remains, led me to search around on the occasion of this 
find which solves so knotty a problem. 
The frequent occurrence of nodules of iron in different rocks, shales, or 
argillaceous deposits, I have never seen ascribed by any writer I have had 
access to, to any cause other than the accidental collection of ferruginous 
matter by molecular attraction; but in the center of such nodules, some 
definite shape is often found ; sometimes a leaf, an insect or only a grain of 
sand ; or, the interior cavity may be filled with ocherous or argillaceous 
matter. 
In the old red sandstone, fossilized fish and plants most frequently show 
a casing or thin cover of a strongly ferruginous nature, which decreases in 
strength with increased distance from the center of the cast in the same 
ratio as one color is blended into another by the artist. 
In the slates and fine sandstones where nodules appear, they either have 
a cavity of loose, ocherous matter—a pyritous speck ora mass of small, . 
strongly sulphurous pyrites in crystals—sometimes only a grain of sand ; 
and in the coarser sandstones between the coal seams, the plants exposed 
on their surface present a dark brown appearance, which shows a red 
streak when the film is thick enough to bear scratching. 
Balls found in the slates and fine sandstones vary in shape as they do in 
size, from a perfect sphere, to irregular oblongs of every imaginable form. 
Now, taking the abundance of fossil fish and other organic remains found 
in some portions of the old red sandstone, may we not reasonably suppose 
that the gray, slaty sandstone, overlying the mammoth coal seam, lying 
low down in our anthracite coal measure, has, in like manner been a re- 
ceptacle for the remains of animal life ; although these remains present to 
the eye more of the appearance and form of potatoes than animal remains? 
Is it not possible that by partial decomposition and chemical action upon 
their tissues and bones, they were converted into a pulpy or gelatinous sub- 
stance which, by the action of the water in which they were floated or by 
the joint attrition of water and fine mud into which their bodies were 
borne, these jelly-like remains were rolled out of all semblance to their 
original organic shape, and then, by the strange chemistry of the period, 
became each a nucleus to which were attracted the minute particles of iron 
converting their remains into the substances and shapes they now bear? 
These thoughts suggested themselves at various times before the finding 
of the tracks in the same bed by the singularly animal-like shape of some 
of the nodules previously met with. ‘‘ Accidental’ shapes they. may have 
been, as I could find no trace of tooth, claw, or bone of any kind, yet this 
does not discourage me from holding to the firm belief, amounting almost 
to conviction, that such discoveries will be made, and by the calling of 
attention to this point by men of acknowledged scientific character, others 
may be led to examine more closely these singularly sown nodules and 
yet more conclusively than these few tracks, establish beyond dispute the 
existence-of animal life in abundance during the period of the formation of 
coal. 
