i8o The Irish Naturalist. Nov. Dec, 



as before, the muscles of the skull relaxed and deteriorated. 

 The muscles most affected in this process -were the large 

 neck muscles whose function is to move the head. Their 

 attachment to the back part of the skull must have gradually 

 become more restricted, with the result that the arching 

 back of the bones above described grew less pronounced. 

 Changes in one part of the skull affect other parts, and thus 

 we may assume that the profound osteological differences 

 between the wild and domesticated pigs were mainly 

 brought about by changes of habit. 



Although the differences in the skull of wild and modern 

 domesticated pigs are so very noticeable that no one can 

 fail to observe them, they are far less so in pig skulls of say 

 a hundred years old than in quite recent ones. In pigs 

 which lived a thousand years ago they are still less 

 pronounced. Let us examine for example a pig skull 

 from an Irish lake-dwelling such as the crannog of 

 Dunshaughlin. This dates from about the loth century. 

 Pig sties and the modern care of pigs were probably unknown 

 in those days. The herds of pigs belonging to such a 

 community as that of Dunshaughlin must have led a semi- 

 feral existence. They probably obtained their food, to a 

 large extent, in the neighbouring woods and forests. In 

 their habits they approached wild pigs much more than 

 modern domesticated breeds do. And these conditions of 

 their existence impressed themselves on the bones of the 

 skulls. The Dunshaughlin pig skulls differ comparatively 

 little from the skulls of wild pigs. Yet they show clearly 

 the early traces of domestication in the shape of the skull 

 and the dentition, and I have no doubt that the skulls 

 discovered in the crannog of Dunshaughlin belong to truly 

 domesticated pigs. If we go a step further to pre-Christian 

 times, many of the domesticated pigs must then have led 

 a state of existence which scarcely differed from that of 

 the wild pig. Even then there may have been colonies of 

 more advanced and better cared-for pigs which were 

 carefully maintained and fattened. But in those remote 

 times we may assume that some of the domestic stock of 

 pigs took to the forest altogether and reverted completely 

 to a feral condition with resultant alteration in the confer- 



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