206 OYSTERS, AND ALL ABOUT THEM. 



memory the fact that this accounts for the large oyster 

 banks or beds which are found in almost all the seas of the 

 temperate and torrid zones, and which in some places have 

 been known to attain such magnitude as to cause ships to 

 be wrecked upon them. And, again, as the reader is aware, 

 the lower stratum is necessarily lifeless, being pressed upon 

 by the upper one, so that the oysters beneath are unable to 

 open themselves, and are consequently deprived of food. 



The immense propagation of the oyster maybe under- 

 stood from the fossil oyster bed near Reading, in Berkshire. 

 These fossils have the entire shape, figure, and are of the 

 same substance as our recent oyster shells, and yet must 

 have lain there from time immemorial. This bed occupies 

 about six acres, forming a stratum of about two feet in 

 thickness. But the largest fossil oyster banks are those 

 raised by earthquakes along the western shores of South 

 America, which measure from sixty to eighty feet in depth, 

 are often forty miles in length, and in many places stretch 

 above two miles into the interior. 



In 1863, Sir John Lubbock published, in the " Natural 

 History Review," an account he had received from the 

 Rev. G, Gordon, of Scotch kjokkenmoddings on the Elgin- 

 shire coast, resembling those in Denmark. Mr. Gordon 

 says : "By far the most striking, if not the most ancient, 

 of the kjokkenmoddings we have in our vicinity, is that one 

 which lies within a small wood on the old margin of the 

 Loch of Spynie, and on a sort of promontory formed of 

 those raised shingle beaches so well developed in that 

 quarter. This mound, or rather two mounds (for there is 

 an intervening portion of the ground which has no shells), 

 must have been of considerable extent. A rough mea- 

 surement gives eighty by thirty yards for the larger, and 

 twenty-six by thirty for the smaller portion. The most 



