GEOLOGY. 



ON THE EELATIONS OF GEOLOGY AND PAL2E0NT0L0GY. 



The following are extracts from the " Roatler" of June, 1865, 

 on the occasion of the puljlication of Mr. T. H. Huxley's cata- 

 Io<;ue of the Jcnnyn-Stret't collection : — 



ralivontology, as a science, shoulil enable us to determine the 

 position of unfamiliar forms, and the age of the strata in which 

 they occur, in the sure hope that observation will verify tlie pre- 

 diction. Mr. Huxley says that a science of geology could not 

 exist, that we sliould only have a numljer of local clu'onologies, 

 did not palieontology combine the sei)arate results, and deduce 

 from them general laws. Wiicn the fossils are identical at two 

 distant places, it should follow tliat palaM)ntologists are agreed aa 

 to the age tlicy indicate. But, twenty-seven years ago, Mr. R. G. 

 Austen threw doubt on the comfortable doctrine that two s(;ts of 

 identical fossils are necessarily contemporaneous and this seem- 

 ing paradox has never since been quite lost sight of. It was 

 further develoi^ed three years ago by the author of this essay, who 

 went so far as to hint the possible coincidence in time of two or 

 more of the great formations. These views geologists pronounced 

 to be errors. It would have been safer to have called tiiem only 

 extreme. This condiMiination starts from tlie assumption that the 

 so-called formations represent epochs in time rather than geo- 

 graphical areas. This idea is perhaps a natural result of the 

 nearly complete sequence, found to exist in the small portion of 

 the globe as yet carefully examined. But to apply it to other 

 parts of the earth's surface is virtually to abandon the law of 

 uniformity of physical processes, and to revive, in a modified form, 

 the doctrine of cataclysms. For, if identity of species proves that 

 the beds containing them are, however far apart, necessarily of 

 the same age, that therefore the same conditions prevniled over 

 ai'eas whose size finds no modern analogy (which ai-e, in fact, now 

 marked by great diversities), it follows that conditions so general 

 could only have been terminated by some cause equally general, 

 though not necessarily violent, in its ojieration, before a new state 

 of things, marked Ijy distinct organic forms, commenced. Hence 

 unconformities, which have been demonstrated to represent longer 

 periods than the formations which they sejiarate, would cease to 

 be of local import. It would be impossible to avoid regarding 

 those separating contemporaneous strata as simultaneous, or to 

 escape the consequent dilemma. For, the axiom that changes ai-e 

 gradual is admitted on both sides, and imijlies tiiat the alteration 

 of conditions, and accompanying modification of structure among 



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