7 
LOCAL OCCURRENCES IN NATURAL HISTORY. 
larger animals may have originally extended* especially where their empire was 
.Undisputed by Man, and they must undoubtedly have been far more numerous 
than in the present day. Geographical circumstances now interpose to limit 
zoological provinces, but different circumstances would permit other results; and 
if Africa and Europe were ever connected, the huge Mammalia of the former, , 
undisturbed in their migrations by a superior power, may have roamed over 
spots from whence, were the communication possible now, civilization would 
stop their progress with its terminating spear. Many geologists seem anxious 
to refer the fossil bones of the gravel-beds to a period “ anterior to the creation 
of Man,” merely on the ground of the absence of human remains. But there is 
no absolute proof in this, as none of the human family might at that period have 
penetrated in this direction; for it is evident that, in early historic times, men 
ignorant and timorous in nautical matters, trusted themselves rarely to the ocean, 
but crowded together with anxious timidity, separating and migrating only like 
the inferior animals, when necessity imposed its inexorable mandate. 
I have before observed, that the matter of the gravel is frequently mixed up 
with battered shells of Gryphcea incurva, as well as a species of Unio , evidently 
washed out of the adjacent Lias formation, which is an additional argument that 
the ocean waves were dashing upon a rocky shore, and accumulating the disin¬ 
tegrating spoils of the pre-existing strata with which they came in contact. In 
this case, then, it seems most consonant to analogy to suppose that the fossil 
bones of the Mammalia found in the gravel, must with other transported debris 
have been brought by oceanic currents, probably from considerable distances, and 
during long intervals of time. I shall subsequently recur to a medium for the 
transport of bones as well as other matter to far distances by a very easy process, 
supposing heat and cold to have alternated in former periods upon the earth, as 
they have ever done in times within the historic notice of mankind. 
Since penning the above, Mr. Murchison's great work on the Silurian System* 
has been published; and as it bears especially upon the point I have been advert¬ 
ing to, and is descriptive of a large district of which I have only touched upon a 
part, I cannot avoid recurring to the views of so accomplished a geologist, after 
the extensive survey taken by him. He conceives that “ all the loose detritus 
which covers the surface of large tracts in South Salop, the North-West of 
Worcestershire, the whole of Herefordshire, and the adjoining Welsh counties, 
may be called local , because it has been derived either from the mountains forming 
the North-Western limits of the country, or from the disintegration of rocks 
occupying the very districts where the materials are found.”-}- Thus Siluria 
(except on its Northern and Eastern borders) being “ exempted from all the far- 
* The Silurian System,hy R. I„ Murchison, F.R.S. 4to. 
f Ibid, p. 510. 
