Rev. W. D. Conybeare's Report on Geology. 433 



We are indeed unable to trace many of these formations, even through 

 our own island, without observing such considerable modifications in 

 their comparative types, in our northern and southern counties, as 

 may sufficiently remind us that we are to look only for such analogous 

 rather than identical results, as would naturally proceed from the con- 

 temporaneous action of similar causes in distant localities ; in each of 

 which many varying local circumstances must have affected those re- 

 sults, for two conditions obviously enter into this problem :— first, 

 the contemporaneous prevalence and extent of similar geological 

 causes; and secondly, how far these causes, even where active, may have 

 been modified bv varying local circumstances. Now, at present, our 

 materials for answering these questions accurately are confined to 

 Europe : of America indeed we have some information ; and although 

 this may as yet be considered too vague to be fully satisfactory, yet 

 as far as it goes it is undoubtedly favourable to the presumption of 

 even a greater degree of geological uniformity than we should have 

 been justified in anticipating d priori. 



" Humboldt indeed has remarked, that while on entering a new he- 

 misphere we change all other familiar and accustomed objects,— while 

 in the plains around we survey entirely new forms of vegetable and 

 animal being, and in the heavens over our heads we gaze on new con- 

 stellations, — in the rocks under our feet, alone, we recognise our old 

 acquaintances. And with regard to the primordial rocks, there is un- 

 doubtedly much truth in this pointed remark. Granite, mica slate, 

 andtheir'contained minerals, present the most identical resemblance, 

 whether we collect from Dauphine, Norway, the Alleghanies, Egypt, 

 India or Australia. But concerning the secondary series, our infor- 

 mation is far less precise. 



" With regard to the comparative geology of secondary districts, the 

 fossil zoologvof the various districts, or comparative paleontology, ^re- 

 quires to be called to our aid as our surest guide. And these investiga- 

 tions are the more interesting, because an important primary question 

 here suggests itself. In the actual state of things, the limited geogra- 

 phical distribution of identical species, both animal and vegetable, is 

 one of the most striking phenomena that presents itself to our view. 

 In distant continents, the specific differences of the animal races are 

 wide and strongly marked ; and sometimes, as in Australia, the differ- 

 ence extends to the character of genera, and even families ; and this 

 even in countries of similar conditions, as to latitude, climate and tem- 

 perature. Now we may naturally inquire, whether it does not seem 

 most probable, that in the ancient geological a-ras the species then 

 inhabiting our globe were grouped together under similar restrictions 

 as to geographical habitation; and if so, how far we are entitled to 

 expect to find in other countries the same series of successive organic 

 remains (each group characterizing a distinct geological sera,) which 

 we meet with in Europe. To illustrate this inquiry :— -If in the pre- 

 sent age the recurrence of violent convulsions were again to submerge 

 Europe and Australia, and cover their surface with fresh sedimentary 

 depositions, these new formations, though absolutely contempo- 

 raneous, would, in either continent, (should they again be laid dry 

 Third Series. Vol. 4. No. 24. June 1884. 3 K 



