some of the Chief $3milkritie* in the 

 aitmt of 



By NELSON M. RICHARDSON, B.A. 



T would, I believe, be generally considered that if 

 two portions of land, not very distant from each 

 other, shewed any striking differences in their 

 fauna or flora, they would be likely to be separated 

 from each other by some considerable barrier, such 

 as a continuous range of mountains, or a wide or 

 deep arm of the sea, the great depth shewing that a long geological 

 period had elapsed since they were united. On the other hand, if 

 we find two pieces of land separated from each other only by a 

 narrow strip of land or water, we expect that they will contain 

 much the same fauna, especially if the soil and general style of the 

 country do not differ much. 



Now the island, or rather peninsula, of Portland does not lie at 

 a great distance from the mainland and the intervening water is 

 shallow. Besides this, Portland is actually joined on to the 

 mainland by the Chesil Beach, an isthmus of about 9J miles long 

 and only 100 200 yards wide for 8 miles of its length. On the 

 mile and a half, or thereabouts, over which the road passes from 

 the Ferry Bridge, it is considerably broader and more or less clothed 

 with vegetation, and at the Ferry Bridge approaches to within 



