ANNIV'ETISARY ADDRESS OF THE PRESIDENT. XXXIU 



the intensity of the local outbursts, the products of which at first 

 glance seem to us the most efficient engines of destruction. It is not 

 the ferocity of battles, but the organic changes among nations that 

 afford us the measure of value or importance of a great war. 



The fourth and uppermost division of M. Barrande's Lower Silu- 

 rians is his " Etage I) ;" strata chiefly composed of quartzites with 

 schistose alternations. Cephalopoda represented by Orthoceras, Pte- 

 ropoda by Conularia and Pugiuncidus, Heteropoda by BelleropJion, 

 Gasteropoda by Plewotomaria and Holopea, Acephala by Avicula 

 and Nucula, Brachiopoda by Orbicula, Lingida, Spirifer, Leptcena, 

 and Terebratula ; also Crinoids, Cystideans, Starfishes, and a few 

 Corals and Graptolites make up, with Trilohites, the fauna of this 

 group in Bohemia. Trilohites and Cystideans prevail above all other 

 forms, and it is in this zone that the former (and the latter probably 

 also) attain their maximum. This fact has a strong significance in 

 its bearing on the hypothesis concerning the relation of Palseozoic life 

 to the life of all after-periods which I shall hereafter bring out in this 

 discourse. The assemblage of animals found in this stage of quartzites 

 constitute M. Barrande's second fauna. He compares the stage with 

 our Llandeilos and Caradocs, with the Lower Silurians of Ireland, 

 Russia, France, Spain, Portugal, and Thuringia, the regions C and 

 D of M. Angelin in Sweden and Norway, and the formations from 

 the Potsdam sandstone to Hudson's River group inclusive, of the 

 United States. The great geographical diffusion of its fauna is in 

 accordance with its vertical extent. But though wddely diffused as a 

 well-marked fauna, exhibiting everywhere a characteristic and easily- 

 recognized facies, the species are by no means universally diffused, 

 and the resemblance between distant regions is maintained rather by 

 representation than by identical forms : thus early in the world's 

 history do we find the partitioning of the earth's surface into natural- 

 history provinces. More and more evident does it become every day 

 that the old notion of a universal primseval fauna is untenable, and 

 that at all epochs, from the earliest preserved to us to the latest, 

 there were natural-history provinces in geographical space. And 

 indeed, if we consider for a moment upon what causes the existence of 

 these provinces depends, how they are not the mere results of various 

 climatal conditions only, but are regulated in their extent in the sea 

 by orographical and hydrographical conditions, and on the land by 

 the inequalities and arrangement of the surface, and thus call to 

 mind that the vast and varying sedimentary accumulations, found at 

 every epoch in gieat mineral dissimilarity, necessarily indicate the 

 existence of those very inequalities and peculiarities on sea and on 

 land that determine the existence and extent of geographical pro- 

 vinces and limit the diffusion of animal and vegetable species, it seems 

 strange to us how the notion of the universal diffusion of a uniform 

 specific fauna could ever have been accepted for a moment, even as 

 an a jiriori hypothesis. It was imperfect recognition of the ph^e- 

 nomena of facies in time, that beautiful idea that first seems to have 

 dawned on the mind of Von Buch, which appears to have given rise 

 to the error. 



