84 DISTRIBUTION OF ANIMALS. [part i. 



fined to Africa and Asia ; but it has now been conclusively 

 shown by Professor Flower that its real affinities are with the 

 racoons (Procyouidae), a group confined to North and South 

 America. In another case, however, an equally careful exami- 

 nation shows, that an animal peculiar to the Himalayas [j^lurus 

 fulgens) has its nearest ally in the Ccrcolcptes of South America. 

 Here, therefore, the geographical difficulty really exists, and any 

 satisfactory theory of the causes that have led to the existing 

 distribution of living things, must be able to account, more or 

 less definitely, for this and other anomalies. From these cases 

 it will be evident, that if any class or order of animals is very 

 imperfectly known and its classification altogether artificial, it is 

 useless to attempt to account for the anomalies its distribution 

 may present ; since those anomalies may be, to a great extent, 

 due to false notions as to the affinities of its component species. 



According to the laws and causes of distribution discussed in 

 the preceding chapters, we should find limited and defined 

 distribution to be the rule, universal or indefinite distribution to 

 be the exception, in every natural group corresponding to what 

 are usually regarded as families and genera ; and so inuch is 

 this the case in nature, that when we find a group of this 

 nominal rank scattered as it were at random over the earth, we 

 have a strong presumption that it is not natural ; but is, to a 

 considerable extent, a haphazard collection of species. Of course 

 this reasoning will only apply, in cases where there are no 

 unusual means of dispersal, nor any exceptional causes which 

 might determine a scattered distribution. 



From the considerations now adduced it becomes evident, that 

 it is of the first importance for the success of our inquhy to 

 secure a natural classification of animals, especially as regards 

 the families and genera. The higher groups, such as classes and 

 orders, are of less importance for our purpose ; because they are 

 almost always widely and often universally distributed, except 

 those which are so small as to be evidently the nearly extinct 

 representatives of a once more extensive series of forms. We 

 now proceed to explain the classification to be adopted, as low 

 down as the series of families. To these, equivalent Eni^lish 



