298 DELIBERATE INTRODUCTION OF NEW ANIMALS 

 THE BEAVER 



Passing reference may be made to an interesting attempt 

 of the late Marquis of Bute to acclimatize the Beaver (Castor 

 canadensis} in Scotland, although strictly speaking the experi- 

 ment has little more bearing on the Scottish fauna than the 

 placing of animals in the Scottish Zoological Park, since the 

 creatures were kept in an enclosure. In the three or four acres 

 of this enclosure, situated in the woods west of Kilchattan Bay 

 in Bute, the Beavers lived happily and prospered so that the 

 four imported (from Canada) in 1874 had increased to six- 

 teen in 1 878. They felled trees, built clams across the stream 

 which ran through their enclosure, erected a lodge and 

 seemed to have thoroughly settled down. Yet in 1890, less 

 than twenty years after their establishment, the Beaver had 

 died out in Bute. 



A similar result ended a similar experiment begun about 

 1868 near Wangford in Suffolk; but there the Beavers were 

 cast derelict by man and had they not been trapped or killed, 

 seemed likely to thrive, for they bred and colonized new 

 localities. 



TRANSPORTED MOLLUSCA 



To what motive do we owe the spread of the tiny Mol- 

 lusca that have been 'placed in artificial ponds and canals? 

 not to the love of beauty, for they are insignificant in 

 appearance, but probably merely to the desire of the collector 

 to have in his neighbourhood a creature in which he took an 

 interest. In any case his activities in this direction have not 

 had much significance. Some Pond Snails, Limncea stagnalis 

 and L. glabra, have been added to the fauna of Scotland, 

 the former occurring, for example, at Possil Marsh, and in 

 a dam at Greenock where it was introduced in 1882, the 

 latter in Frankfield Loch, where it was placed before 1876. 

 The little Sph&rium lacustre, once absent from Scotland, 

 now occurs through man's agency in the Forth and Clyde 

 Canal and in Possil Marsh near Glasgow. 



"ESCAPES" 



Occasionally it happens that animals deliberately brought 

 into the country to be kept as pets regain their freedom and 



