BATKAOHIA, AND MAMMALIA. 477 



act ill adapting the isolated portion to its new conditions, and 

 will do this more quickly and the more effectually because of 

 the isolation." 



It is evident then that our voles, whether they originated 

 from the species now present on the Continent, or, as I think 

 the more probable, are Avith them, the descendants of a com- 

 mon stock, have found in these islands some conditions in 

 food supply or in physical environment other than those which 

 obtain on the mainland, and have adapted themselves accord- 

 ingly. 



How long these conditions of isolation have operated we 

 have seen in the preceding pages dealing with the physical 

 geography of the islands. 



OUR ANIMALS OF THE RECENT PAST. 



In these islands, denuded as they are of all i:leposits down 

 to the granite, diorite, and Cambrian schists, we do not of 

 course expect to find traces of the earlier forms that occupied 

 their areas. But of those which lived here on the borders of 

 the historic period the forest bed furnishes some evidences. 

 In the peaty soil, and in the clay just below it, we find the 

 remains of the ox, pig and deer. 



The ox is Bos longifrons^ and must have roamed these 

 lands in considerable numbers, for wherever the peat is opened 

 to any extent there its bones are found. It is, however, only 

 when excavations for foundations of walls are made that the 

 peat is thus disturbed. 



The remains which have come under my own observation 

 are as follows : — In the excavations for the foundation for a 

 short length of sea wall at St. Ouen's, one entire skeleton, a 

 separate skull and many loose bones. In the excavations for 

 the foundations of St. Paul's Church in St. Helier's, one 

 entire skeleton. In the cutting for the railway at St. Cle- 

 ment's, loose bones (these were in clay). Several bones 

 washed from the peat in St. Aubin's Bay. Loose bones from 

 the ])eat in Vazon Bay and L'Ancresse Bay, Guernsey. In 

 all the cases in Jersey the bones are associated with flint 

 chippings and flint implements of rudest type. These flints 

 may of course have been in the soil prior to the bones, but I 

 found a jaw of this ox in the cliff cave at St. Ouen's, known 

 as Jai Cotte a la Oierre^ with a mass of flint chippings and 

 implements. It had no doubt formed a part of the larder of 

 the dw^ellers in that cave. 



This large mammal must have lived here for a long 

 period for, as we have seen, it reached Guernsey, and Avas 



