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 (Procyonidas), 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 (JEluvus 
fulgens) has its nearest ally in the Cercoleptes 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 much 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 inquiry 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 English 
