291 Proceedings of the Royal Physical Society. 
ment leading to the belief that the writer had seen the end 
of the wall, wliile we ascertained as a certain fact, that it had 
not been above ground and visible as a wall for at least 250 
years. With regard to the termination of the wall near 
Henry Bell's monument I have nothing to say; but in regard 
to its eastern extremity I must remark, that it must have 
risen 75 feet higher than was necessary since the Eoman 
epoch, to suit the theory of Geikie and Lyell, if the Eomans 
meant it as a defence against the incursions of the Scots. 
Further up the Forth, near Inveravon, occurs a large 
deposit of oyster shells. They may be obtained in cart-loads, 
and have furnished Mr Maclaren and others with a very 
feasible argument for the supposed rise of the shores of the 
Forth. They have contended that this bed is in situ, and 
affords all the evidence necessary to prove their position. 
Now, on examination of this very long-continued bed — for 
it appears only a little to the westward of Bo'ness then very 
thin and low, and increasing in depth and quantity of 
shells as we proceed westward, which two points I wish the 
Society to remember, it culminates at a point near Inveravon, 
a few hundred yards above a house, near the road-side, cele- 
brated as the birthplace of the late Principal Baird of Edin- 
burgh — how were these oysters lifted from their oozy beds 
and placed here at least 60 feet above high-water mark 
is the question, and from whence did they come ? Maclaren 
and others affirm this as a proof of the rise of the oyster-bed 
to its present level, the former geologist asserting that 
oysters are pelagic, and only found in six fathoms water at 
least. 
Now, what are the simple facts of this case ? Let any 
one who hears me go to the spot, and he will find no 
trace of a marine bed below his sub-aerial oyster-scalp, 
but a fine deep bed of humus. Further, he will find 100 
oyster shells of large size for one whelk or any littoral 
shell, proving, at least, to any one with a slight acquaint- 
ance with dynamics, that a great surging wave of trans- 
lation could lift these oysters and place them in their 
present position high and dry when the wave retired, 
leavingjthem, as we now find them, over a fine bed of soil 
