90 Proceedings of the lioyal Physical Society. 



of Scotland. The limpet, and samples of some more species 

 of shell, are to be picked up. One of them {Tapes decussata) 

 claims special notice. Its remains hold the fifth, if not a 

 higher place, in the shell mound at Brigzes. It is not 

 known to exist now in the Moray Firth ; and (upon the best 

 'possible* authority on such matters) the most northerly lo- 

 cality where it is now found alive is the coast of Carnarvon- 

 shire. It seems to form a striking exception to the rule. 

 While the other species, that are now extinct on our shores, 

 are withdrawing to the north, and are found alive only 

 towards the Arctic Circle, this species, once frequent, bat not 

 now known with us, has withdrawn in the opposite direction 

 — to a warmer latitude. 



There is evidence enough in these mounds, and of a like 

 nature as that drawn from the Danish accumulations, to show 

 that they have been the work of man. and not the effect of 

 any tidal current, or of any other natural cause. The shell- 

 fish which these remains represent are, with scarcely an ex- 

 ception, edible, and continue to this day to be eaten. In all 

 deposits by the sea there is abundance of species that have 

 ever been rejected as food. The shells are full-grown or adult 

 shells. In collections made by the sea, the young animals 

 are abundant, and often predominate. 



Now, no movements of wind or water could have thus se- 

 lected the edible and the adult, and .left behind the noxious 

 and the young. They must have been gathered by man, 

 and for the purpose of supplying his wants. Many other 

 arguments have been brought forward to prove this, so that 

 there is now no doubt entertained about the matter. One 

 strong proof is, that the oyster and the periwinkle are never 

 found living and mingled together in the same part of the 

 sea. The former exists between tide marks, the other in 

 deep water. The cockle delights in sand ; the mussel must 

 be moored to a rock or hard bottom. In different parts of 

 the masses of shells at Brigzes, there are to be seen many 

 stones that have been subjected to considerable heat. They 

 probably have been used in this state for cooking, as is 

 known to be the case among people of primitive habits to 



* Kobert M' £ Andrew, Esq., London. 



