62 THE POPULAR SCIENCE MONTHLY. 



were crowned with fronds of marvelous dimensions ; the stems of the 

 sigillarias shed their leaves rapidly ; and the remains of all these rank 

 growths were incessantly accumulating in a sultry shade on a water- 

 soaked soil. We can conceive the enormous production of humus. 

 Decomposition was accelerated by every rain, and the whole mass was 

 reduced, down to the very bottom, to a black pulp ; and this is why, 

 notwithstanding we have such abundant materials, we meet so many 

 difficulties in reconstructing the types. The fallen trunks seldom re- 

 mained whole, but swelled and burst. The soft and porous parts gave 

 way first, then the dense and fibrous parts were detached from the 

 cortical mass ; that, more tenacious and firm, spread out and resisted 

 longer than the rest. Nothing remained of the fern-stems but the 

 peripheric sheath or the disaggregated interior fibers ; of the cordaites, 

 sigillarias, and lepidodendrons only the cortical regions. The detached 

 leaves formed other accumulations ; and all these heaps, standing as 

 obstructions in different places, were waiting for the arrival and pas- 

 sage of the water to yield to it innumerable fragments in very unequal 

 degrees of decomposition. When the great rains came on, the waters, 

 filtering in from every side, trickling down all the slopes, gathered 

 here and there in temporary lakes, and finally overcame all the dams 

 of organic matter they met an immense mass of detritus going down 

 to the lacustrine center. With these old and disorganized residues, the 

 rains, which we must imagine to have been torrential, brought down 

 also everything that would yield to their impulsion tree-trunks, 

 leaves, young shoots, and at times entire plants. It is these remains, 

 so fresh in condition, these leaves so delicate, and clearly defined, these 

 organs so whole which we see in our collections distinguishable in their 

 slightest details, and lying spread out in the leaves of the great herba- 

 rium of which it is our privilege to turn the pages. 



M. Grand' Eury's theory does not appear to offer anything that is 

 discordant either with ancient phenomena or with those of more recent 

 periods. It possibly has its place marked even now among the grand 

 scenes of contemporary nature. We read in the narratives of the travel- 

 ers who have ascended the great rivers of the interior of Africa, the 

 Nile, for example, how their boats have been stopped for days at a time 

 by submerged remains and the accumulations of plants hiding the river 

 on which they were floating. In the face of such pictures, which show 

 us sedges, water-lilies, and immense colonies of floating plants, under 

 which the river has disappeared, while its eddies, its lagoons, and its 

 deep basins are temporarily flooded after having been dry for months, 

 we can not escape being carried back in mind to the phenomena, doubt- 

 lessly not quite parallel, but assuredly of the same order, to which was 

 due the formation of the coals and lignites in ancient epochs. These 

 were certainly not accidental or episodical phenomena, produced by 

 circumstances which, once realized, were never to appear again, but 

 occurred in the course of a series of analogous combinations of condi- 



