BRITISH POSTGLACIAL <5» RECENT DEPOSITS. 429 



harpoons, and canoes to testify to his former presence. When 

 the sea had retired to the 25-30-feet level, however, a knowledge 

 of metals had already been introduced, as we learn from the 

 fact that various objects of bronze and iron have been met with 

 embedded in the estuarine and marine deposits of that stage. 

 Now, in certain districts, upon the upper surface of this later 

 marine terrace and in old sea-caves pertaining to the same level 

 kitchen-middens and other finds occur in which we meet with 

 no trace of metal. This shows us that even after a knowledge 

 of metals had been introduced to Central Scotland, there were 

 people living in northern and other outlying parts of the coun- 

 try who were either entirely ignorant of the use of bronze and 

 iron, or too poor or too far removed from the metalliferous dis- 

 tricts to obtain them. At what particular time the sea retreated 

 from the 25-30-feet level has been a much disputed question. 

 But if one may trust to the evidence supplied by local names, 

 the change took place after the land had been occupied by a 

 Celtic-speaking people. Thus, in the Carse of Gowrie, we find 

 prominent mounds, which must have been islands during the 

 formation of the 25-30 feet beach, designated as Inches, from the 

 Gaelic " Inis," signifying " island." 1 



1 For an interesting paper on this subject by the Rev. Dr. Milroy, see Scottish 

 Naturalist, April and July 1880. 



