president's address. 223 



Mr. Darwin's ssecular inch. The highest cliffs are worn down 

 often with greater rapidity than the lower. The sea would work 

 against the perpendicular faces of chalk. We know that, at 

 Whitburn, the whole camping ground of the Sunderland volun- 

 teers, during the late war, has been, in forty years, completely 

 absorbed. The same process continues. At Castle Eden, there 

 are portions of the Black Hall rocks which, in the memory of 

 persons now living, were connected with the mainland, which are 

 now 150 yards below high- water mark. Surely Eeculver and 

 Richborough, in Kent, Beachy Head, in Sussex, the parishes 

 Consumpta per 3Iare, in Norfolk, might have induced Mr. Darwin 

 to modify his demands on time. 



But now he comes to the great difficulty — which he very 

 frankly confesses — that the fossiliferous strata afford him no evi- 

 dence, and that there are sudden appearances of whole groups of 

 allied species in the various formations, which continues without 

 variation to the close of the epoch. He observes, " that when the 

 same species occur at the bottom, middle, and top of a forma- 

 tion, the probability is that they have not lived on the same spot 

 during the whole period of deposition ; but have disappeared and 

 re-appeared, perhaps many times, during the same geological 

 period. So that, if such species were to undergo a considerable 

 amount of modification during any one geological period, a 

 section would not probably include all the five intermediate 

 gradations which must, on my theory, have existed between them, 

 but abrupt, though perhaps very slight change of form." This 

 does appear to me a petitio principii, and an argument from igno- 

 rance. 



In the career of hypothesis, we come upon a yet more startling 

 assumption. In the Silurian rocks, we find remains at least as 

 distinct from each other as those now obtained on our coasts, and 

 two genera of Molluscs, which are still represented in our fauna. 

 It has been observed that, in order to account for this, Mr. Dar- 

 win does not hesitate to plunge back into the eons of past time, 

 and to point to a period as far remote from the earliest known 

 Palaeozoic rocks as these are from our era. Not knowing where 

 to find a shred of evidence, for the existence of this enormous 



VOL. IV. PT. Ill, 2 D 



