30 The Treasures of Siluria. [Jan., 



Preceding the lists of species which form the main body of the 

 work, Dr. Bigsljy records a number of " Facts and Observations " 

 as the result of his analysis of them. These general conclusions 

 bear even stronger testimony to the author's industry, and much 

 more powerful witness to the vigom* of his intellect, than the hsts 

 of species themselves. Indeed, if the ' Thesaurus ' had been 

 placed in the hands of a dozen Palaeontologists, we doubt whether 

 any one of them would have drawn a more original series of 

 inferences than these same " Facts and Observations ; " and we are 

 quite confident that a more suggestive series it would be impossible 

 to bring together. 



While it would be both tedious and difficult to scrutinize lists 

 of species, it is infinitely easier to criticize conclusions than it is to 

 arrive at them. The reviewer comes to their examination rather 

 inclined to object to them, while the author, on the other hand, 

 having been for weeks, for months, perhaps for years, accumulating 

 and selecting materials which have suggested to him certain in- 

 ferences, finds it extremely difficult fully to appreciate such hostile 

 facts as would require very serious modifications of his pre^aous 

 results. 



Having thus confessed our bias, we will endeavour to guide our 

 readers fairly through some of the paths trodden by our author, 

 and will commence with that very intricate formation known as the 

 " Primordial Zone." 



Although the commencement of what is still included in the 

 "Silurian System" may not be of the greatest importance to the 

 registrar of the births and deaths of Palaeozoic fossils, there is no 

 doubt whatever that it possesses the highest interest for the scientific 

 theorist. The " Primordial Zone " must, in fact, be stiU looked 

 upon as practically the natal epoch of organic hfe, for the m- 

 habitants of the vastly more ancient Laurentian period are still too 

 little known to enable the Palaeontological genealogist to deal with 

 them. 



Dr. Bigsby devotes three or four pages to a brief sketch of the 

 sahent facts connected with his census of the inhabitants of the 

 Primordial Period, but owing to his apparent desire to extend its 

 limits, he is obhged to commence with the following sentence : — 

 " Waiting for the results of the investigations now taking place in 

 Canada as to the exact relations of the Quebec Group with the 

 Primordial Stage, it will be better not to dwell long on this part of 

 the Sihirian Epocli, especially as the present ideas on these relations 

 do not give entire content." He further remarks that "it is 

 indissolubly Silurian by almost every possible tie — by facies, 

 materials, stratigraphy, and organic contents," — but in this latter 

 conclusion he will not be supported, we think, by our working 

 Welsh geologists. 



