PENGELLT FOSSILS OF DEYON AND CORNWALL. 
27 
they are. But the adverse witnesses are by no means agreed amongst 
themselves ; eight of them claim the rocks for the Silurian age, and 
tift3^-eight for the Carboniferous. Is there no way of silencing, and 
yet satisfying, these doubtful characters ? i!\o method of so inter- 
pretiug their testimony but that of sacrificing the Devonian system 
altogether ? Are they not so many arguments in favour of the gradual 
passage of system into system ? So many difficulties in the way of 
a belief in catastrophes, by which I mean convulsion or other form 
of violence (call it what you please) which, from time to time, shook 
the very life out of the world, causing a seizes of universal and syn- 
chronous depopulations of our planet ? May we not regard them as 
so many tints intermediate, both in place and quality, between the 
extreme bands of the rainbow, uniting them into one beautifully 
graduated chromatic spectrum, so softly blending as to render it im- 
possible to define the exact place of lines of demarcation, which, per- 
haps, have not, and never would have been supposed to have, an ex- 
istence, had not observers hastily generalized from the imperfect 
evidence obtained during a period of colour blindness? 
May we not regard them as just sixty-six pages in the old parish 
register connecting three otherwise unconnected portions, and sliow- 
ing that the population was not, during their time, cut off sharply, 
universally, and at once, whether by pestilence, war, or famine ; but 
that the old inhabitants gradually disappeared, and that many of 
them remained amongst the new comers, discharging their accus- 
tomed functions under the somewhat changed conditions ? 
But if the Devonshire rocks were handed over to the Carboniferous 
or Silurian system, or divided between them, we should not be quit 
of the doctrine that some of the forms of one period have, at least 
in some instances, lived through it into the next ; for the opponents 
of a Devonian period not ouly admit, but rest their case on the 
alleged fact that Silurian and Carboniferous forms are found blended 
together in Devonshire and elsewhere. 
When, nearly a quarter of a century ago, Mr. Lonsdale first sug- 
gested that the fossils of South Devon, taken as a whole, exhibited a 
peculiar character intermediate to those of the Silurian and Carboni- 
ferous groups, he was perfectl}- aware that amongst them were forms 
referable to each of these Faunas ; yet he made the suggestion, not- 
withstanding the existence of a physical objection, subsequently 
removed by Professor Sedgwick and Sir E. I. Murchison, who dis- 
covered that the culmiferous or anthracite shales of North Devon 
(superposed on the rocks we have been considering) " belonged to 
the coal, and not, as preceding observers had imagined, to the tran- 
sition (Silurian) period."* 
And what has been the effect of the progress of discovery and 
nicer discrimination on this point ? Has it increased or decreased 
the evidence in favour of a Devonian period ? In 1846, Sir H, De la 
Beche, discussing this question, gave a total of a hundred and ninety 
species noticed in South Devon, which he thus disposed of : seventy. 
* Lyeffs ' Manual,' 5tli edition, p. 424. 
