546 THE AZOIC SYSTEM AND ITS SUBDIVISIONS. 



evolutionists who accept the Eozoun in a more difficult position than 

 they would occupy if they rejected it altogether. It would be better 

 for them to take the ground occupied by F, Roemer, and say that " the 

 strata containing the Primordial Fauna are the oldest fossiliferous rocks, 

 eitlier because the rocks which arc still older were originally vmsuited 

 to the preservation of traces of life, or had become so in consequence of 

 subsequent changes, or else because the organisms which preceded the 

 Primordial Fauna were of too perishable a character to be preserved." 

 At all events, let them recognize, with Roemer, that, so far as our pres- 

 ent knowledge goes, there are no fossils older than those of the Pri- 

 mordial Fauna. 



Of all the results of geological and palacontological investigations 

 during the past half-century, there is no one so remarkable as the reve- 

 lation of the existence of the so-called Primordial Fauna. It is now 

 clearly established that there was a time when life was represented by 

 a few forms, which were essentially the same all over the globe. What 

 has long been known to be true for Europe and America has been 

 recently supplemented, for Asia, by the investigations of Richthofen in 

 China, where the peculiar primordial fauna seems to be largely devel- 

 oped, bearing, as Professor Dames remarks,* "an astonishing resem- 

 blance " to that of North America and Scandinavia. We have, namely, 

 in China, the same intermixtui-e of trilobites, either belonging to the 

 genus Concocephalites, or closely related to it, together with the usual 

 primordial brachiopods, Orthis and Lingulella, which everywhere char- 

 acterize the oldest rocks in which any " decipherable traces " of life 

 have been found. And, as if in utter contempt of all theories, we find 

 the trilobites disappearing entirely in early geological times, while the 

 brachiopods remain almost or entirely unchanged up to the present 

 epoch. 



We have thus, as we think, clearly established the truth of the state- 

 ment, that the stratified rocks designated as Azoic by Foster and Whitney, 

 and included within the Archsean of Dana are — so far as present evidence 

 goes — non-fossiliferous. A persistent search for nearly half a century, 

 in all parts of the world, for traces of life in infra-Silurian formations 

 has not resulted in success. We consider, therefore, that geologists who 

 prefer the guidance of ftxct to that of theory, and who respect the law of 

 priority in nomenclature, will continue the use of the name Azoic for 

 the rocks described under that name by Foster and Whitney. At the 

 same time, it is desirable that a more definite understanding should be 



* China, Vol. IV. p. 7. 



