322 NATURAL SCIENCE [November 



series of stratified rocks in a continuous chain and to unerringly 

 distinguish any particular horizon in discussion by its particular 

 ear mark, namely, the special fauna and flora whose debris are 

 found in it. 



This I need not say is the corner stone of modern strati- 

 graphical geology, and this, so far as we can see it, will remain. 

 I have nothing to say about the key which is an absolutely in- 

 dispensable one. What I propose to criticise, however, is the 

 arrangement founded upon the facts thus ascertained, and I 

 propose to attack it in two ways and on two grounds. If our 

 object is to ascertain the past sequence of events in any particular 

 spot on the earth's surface, we cannot do better than make a boring 

 at the particular spot and describe in detail the successive beds 

 lying upon one another or which we can fairly conclude once lay 

 upon one another in that particular spot. This will undoubtedly, 

 so far as that spot is concerned, give us the sequence of events. 

 If the record be complete it will, of course, be a complete story. 

 If some pages be torn out of the book it will, of course, be in- 

 complete. This we may or we may not be able to infer. What 

 is clear is that the column of different strata thus pierced represents 

 not a general universal geological pedigree, but the geological 

 pedigree of one particular spot only. This, of course, is universally 

 admitted. No fact is more elementary than that two wells dug 

 in the same parish may present us with very different columns 

 of strata. Some thin out, some grow thicker, some disappear, 

 and some make their appearance. The one cardinal fact, however, 

 remains, that so long as we remain in the same " Zoological 

 Province " so long will these beds when found together be found 

 arranged in the same order. 



This being sj3 it is perfectly justifiable and perfectly logical so 

 long as we remain in the same zoological province to collect all the 

 beds occurring within that province and to arrange them in 

 sequence, and having done so to make that sequence a test and 

 touchstone by which the relative position of any particular bed in 

 any particular section may be ascertained ; always remembering, 

 however, that we do not mean by this arrangement that the 

 sequence of events in every spot within this area was precisely the 

 same. In some cases certain stages were possibly absent as the 

 record seems to infer, or a particular stage in one area may have 

 become a complicated series in another. These are, however, 

 mutters of detail in which we have no necessity to guard ourselves 

 since they are obvious and simple. What it is important to 

 remember, and what has been made the subject of adverse comment 

 by more than one distinguished palaeontologist, is the fact that the 

 arrangement we have been considering only holds good and is alone 



