I NT ROD UCTION. 2 1 



Lastly, as has been already said, Grand' Eury 1 has quite recently 

 adopted an intermediate view on the strength both of botanical investi- 

 gation and of long mining experience. He brings forward a number of 

 facts which are opposed to Goppert's reasons for pure autochthony, and 

 does not rest his argument solely on the stratified condition of the seams 

 of coal, as Giimbel 2 supposes, for this would not suffice for his purpose. 

 The picture which he draws of the state of the surface of the earth when 

 coal was formed may quite possibly come very near to the reality. 



It is a known fact that fossil remains are usually found in a flat- 

 tened condition ; it would appear from many observations of Goppert, 

 Grand' Eury, and others that this is the case also in coal. The cause of 

 this phenomenon is usually alleged to be the pressure exerted by the over- 

 lying masses of stone, and this same pressure we have become accustomed 

 to regard as the main factor along with the effects of heat and water in the 

 formation of coal. Grand' Eury shows most convincingly that this action 

 of pressure, if there was any, can have been of only very small importance, 

 In the famous angular siliceous pebbles discovered by him at Grand' Croix 

 near St. tienne, which inclose the petrified material of a layer of coal in the 

 act of formation, the remains of the plants are for the most part in a 

 flattened form, although they lie loosely on and over one another in the 

 pebbles, and there is no trace whatever of any pressure. Both in these 

 pebbles and in normal seam-coal we have the most abundant proof of the 

 remarkable fact that these flattened stems, roots, and branches consist 

 wholly of a tube of rind, from which the inner tissues, and especially the 

 woody axes, have been removed. This is the case not only with the 

 Lepidodendreae with thick succulent rinds, but also with the Cordaitae 

 which had larger woody bodies and must therefore have been of a much 

 less succulent character. It is observed also that if the tubes of rind still 

 embrace their cylinder of wood, the latter is commonly split into irregular 

 fragments which are often displaced ; sometimes single fragments are still 

 found in their place and position while the rest are removed. It is further 

 remarkable that the tubes of rind are very frequently slit up on one side, 

 and then rolled over at one margin of the slit ; as a rule also they occur 

 only in pieces of moderate length, entire stems being rarely found in the 

 seams, though, according to Goppert, these seem not to be so infrequent in 

 Upper Silesia. Now if coals are of purely autochthonous origin, all these 

 circumstances must appear very strange ; on the other hand they are quite 

 intelligible, if we suppose them to result from the action of a slow stream of 

 water overflowing ground covered with dead and decaying trees and frag- 

 ments of plants. We can imagine how in such a case the softened and 



1 Grand' Eury (2). ' Giimbel (2), p. 206. 



