FUCOIDES IN THE COAL FORMATIONS. 



325 



the marine vegetation of old. Small species of Hydrophytes, in our time, afford sufficient 

 analogies. The great bank of Sargassum, which extends between the 20th and 45th 

 parallel of latitude, covers, according to Humboldt's computation, a space of more than 

 260,000 square miles. In places this floating bank is so thick as to arrest the progress of 

 vessels, and it appears at present to be of the same extent and to occupy the same place 

 as when it was first noticed by navigators. What can we then infer to have been the re- 

 sult of a vegetation whose force was at least double of what it is now, and which has 

 written its history in whole strata of great thickness'? 



§10. ANALOGY OF LIFE AND FUNCTIONS IN BOTH THE TERRESTRIAL AND THE MA- 

 RINE VEGETABLE WORLD. 



It cannot be presumed that this whole vegetable world of Paleozoic seas has left 

 nothing after it but useless petrified remains. In the march and development of nature's 

 productions, nothing of the materials employed is ever lost. The smallest atom of matter 

 is preserved in some way, if not constantly remodelled. Thus we find the key of a new 

 lift-, of a new creation, in the remains of a destroyed one. Thus, some leaves, preserved 

 by fossilization, in the shales of the Coal Measures, open to our view not only the whole 

 world of an ancient vegetation, but its predestinated result, coal deposits, slowly laid up 

 by its agency. Tims also the remains of marine plants, in the shales of the Devonian, 

 point out, I think, not only the fecundity of an ancient marine vegetation, but its result 

 in the contemporaneous deposits of petroleum. Indeed, both kinds of vegetation have 

 great analogy of life, if not of organism. The plants of the coal, by their structure, the 

 form of their long pointed leaves or indefinitely divided fronds, were shaped for the absorp- 

 tion and the transformation from the atmosphere of the greatest amount of carbonic acid 

 gas into woody tissue. The Chlorosperm of the Palaeozoic times, with their simple; bladdery 

 conformation and their green color, were undoubtedly prepared to perform in the water 

 the same functions as the coal plants performed in the atmosphere. As the result of ter- 

 restrial vegetation has been, first woody tissue, and then, by its decomposition, coal, so the 

 result of marine vegetation has been, first cellular tissue, filled with a kind of liquid 

 carbon, and as the carbon is unalterable, the decomposition of the plant has left it free as 

 fluid bitumen or petroleum. 



§11. VV It AT CHEMISTRY I N 1) I A T BS ON T H E S II B J E C T. 



We cannot follow, in our day, by means of the accumulated remains of Hydrophytes, 

 the slow process of carbonization, and compare its results at different stages of its develop- 

 ment, as we can by help of the remains of land plants, in the formation of peat bogs, lig- 

 nites, &c. This only has been observed: When marine vegetables are thrown upon bogs 

 and mixed with terrestrial plants as compound of tin; peat, they do not leave any trace of 

 organism or primitive form, and the peaty matter, then of a deeper black color, is a softer, 

 more homogeneous compound, richer in bitumen. When, detached by storms or tides, A Lgse 



