2M Proceedings of the Boyul Physical Society. 



ment leading to the belief that the writer had seen the end 

 of the wall, while 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, 

 leaving 'them, as we now find them, over a fine bed of soil 



