164 ' The Post- Pliocene Non-Marine Mollusca of Ireland.' 



lusca of Ireland ' originated in Germany, the earlier evolved and 

 therefore more primitive types being gradually driven farther 

 and farther away from the evolutionary centre.' The grave 

 misconception of those authors as shown by their arguments 

 that every species is believed to arise in North-central Europe, 

 a region by no means synonymous with Germany, as Kennard 

 and Woodward persistently phrase it. 



If Kennard and Woodward will more carefully peruse the 

 original, they will learn that all that is claimed is, that the 

 chief types of life originated in the North-central European 

 region,* and that evolution in a lesser degree is a characteristic 

 of every region, f and it is nowhere denied that species and 

 varieties do become evolved in every country by the influence 

 of the special organic and inorganic environment to which they 

 are subjected. 



Even Australia, + though so evolutionary feeble, has de- 

 veloped a rich variety of species, but with little or no material 

 advance in structure. In this connection it is to be noted that 

 even Kennard and Woodward allow that in Oligocene and 

 Miocene times a varied Molluscan fauna existed in Western 

 Germany and Bohemia, containing probably the ancestral 

 forms of some of our living species and though they state that 

 these forms have also been found in Switzerland and France, 

 and especially in the South-west of France, they give no 

 information as to the geological age of the deposits there. 



With the view of upholding their own erroneous interpreta- 

 tion of my theory, the authors classify the Molluscan fauna 

 into several groups. The first is based upon the presence of 

 eighteen Gastropods and several Pisidia in earlier strata in 

 this country, than in Germany. A second list shows twenty- 

 two species now living in England which are not known in 

 Germany, living or fossil. A third list enumerates eight 

 species formerly resident here, quite unknown in Germany. 



These lists, though not perfectly accurate, agree in the 

 m.ain with the present imperfect palaeontological knowledge, 

 but are published with the special purpose of showing by the 

 evidence they offer that species have or may have originated 

 in this country, a statement which has not been disputed. 



The geological record and our knowledge of it is too frag- 

 mentary and incomplete for final conclusions, and cannot in 

 its present stage overthrow decisions based upon the solid 

 facts of structure and distribution by the merely negative 

 evidence it may offer, evidence also peculiarly liable to con- 

 tinual alteration and correction by the results of future dis- 



* Monograph, Vol. I. p. 387. 

 t Monograph, Vol. I., p. 401. 

 + Monograph, Vol. I., p. 388. 



Naturalist, 



