12 GEOLOGY OF THE LOTHIANS. 



tions, (the relative ages of which were indicated by superpo- 

 sition) we must expect to find in the oldest of these forma- 

 tions or series of strata, individuals of this natural class 

 having a more simple structure than those imbedded in the 

 newest. But it was insisted, and is yet (though some ima- 

 gine that they see in the laws which now govern organized 

 bodies in all their relations, and in the globe itself, an almost 

 eternal and uniform system of legislation), that the earth's 

 strata exhibit proofs from their contents, that certain epochs 

 have been characterized by the creation of the several main 

 links of the zoological chain. 



The term " Transition"" has been discarded by a celebrated 

 geologist upon another ground ; but unfortunately the rea- 

 son why the term was applied has been misunderstood. Mr 

 Phillips, in his " Guide to Geology," after saying, that some 

 geologists make a Transition class of rocks, affirms " that 

 this is needless, for such passages are not thought necessary 

 to be marked in other instances. 11 When Werner named a 

 certain class of rocks " Transition, 11 it was done, not from 

 discovering that they passed into the inferior or more crystal- 

 line rocks, but from the conclusions which he drew from find- 

 ing, that, in this series, for the first time, marks of animal 

 and vegetable life occurred ; and that these were remains of 

 beings which possessed a structure of the most simple na- 

 ture. He so named this series of rocks, not because it pass- 

 ed by mineral character, or alternation, into his " Primitive 

 class ;"" but because his examination of its contents, and 

 relations to associated rocks, made him draw the inference, 

 that it had been formed during the passage of the globe, 

 from a state in which vegetable and animal life existed not, 

 to one fitted for its preservation.* The term " Transi- 



* " They are supposed to have been deposited during the passage or 

 transition of the earth from its chaotic to its habitable state." — Jameson's 

 (leognosy, p. 140. Edinburgh. 1808. 



