210 GEOLOGICAL RELATIONS OF THE ROCK SYSTEMS 



accurate and detailed parallelism to be established between the rocks 

 in both these countries, portions of which were now known to be syn- 

 chronous : and that, while in all probability, it would be found, that 

 starting from the common datum line of the coal-bearing rocks in 

 either land, the sequence upwards would be established from Indian 

 researches in this country, apparently supplying links wanting in 

 Australia; on the other hand we should be enabled to supplement 

 the evidences of the succession downwards (which is deficient in 

 India) by a reference to Australian groups. As yet we have not been 

 able to trace the existence of any marine deposits in this country, of 

 the same age as the " Wollongong" sandstones of Australia, but there 

 is nothing whatever in the few plants which occur in our Talchir beds 

 which would militate against their being of the same general age, 

 (which I am disposed to think they are). 



But such speculations are, perhaps, premature, and I have no doubt 

 whatever that, as our detailed investigations progress, each successive 

 group will find its appropriate place. 



But it is certainly not by any forced assimilation, or any narrow 

 parallelism with European types that this end is to be gained. Each 

 country, each district, each basin, must be examined by itself, and 

 for itself, and long before the slightest attempt at any true identifica- 

 tion of the smaller sub-divisions or beds can safely be made we 

 must have a far wider, and a far more accurate, knowledge of the 

 stratigraphical relations, and of the geographical area, of each of the 

 larger systems. 



And even then we must never forget that we are dealing with the 

 remains of animals and plants which once lived in countries, separated 

 from the typical localities with which we attempt to correlate them, 

 by half the surface of the globe ; that there were as truly zoological 

 and botanical provinces in earlier periods of the earth's history as there 

 are now : that the atmosphere, the elevation, the climatal conditions 



