DISTRIBUTION OF ANIMALS 89 



The numbers for Dorset are obtained by omitting all 

 the " stragglers " and very rare visitors, including all that are 

 regular immigrants or birds of passage, as well as those 

 which, though irregular, are tolerably frequent visitors. Here, 

 again, we see that a county area has rather more than half 

 the British species, as was the case with flowering plants and 

 some of the most extensive orders of insects. 



The difficulty of obtaining really comparable figures for 

 the following countries and regions is at present insuperable, 

 but the approximations given are of considerable interest. 



Table of the Species of Birds 



The numbers for the Oriental Region have been estimated on the method of 

 Mr. Shipley above referred to ; and the same has been done for the Neotropical 

 and Australian Regions. 



The numbers for Central America and Mexico have been reduced from those 

 of the Biologia Am. Cent., because that work includes all temperate Mexico 

 with a large number of Nearctic species. 



The preceding table exhibits several points of interest, 

 especially as regards the correspondence of the proportionate 

 numbers of such different organisms as birds and plants. 

 As regards the Palsearctic and Nearctic regions (temperate 

 Europe and Asia on the one hand, temperate North 

 America on the other), we see that the birds of the former 

 are about one and a half times those of the latter, the areas 



