The geographical distribution of animals, with a study of the relations ...

84 DISTRIBUTION OF ANIMALS. [part i.fined to Africa and Asia ;but it has now been conclusivelyshown by Professor Flower that its real affinities are with theracoons (Procyonidae), a group confined to North and SouthAmerica. In another case, however, an equally careful examinationshows, that an animal peculiar to the Himalayas (JZlurusfulgens) has its nearest ally in the Cercolejrtes of South America.Here, therefore, the geographical difficulty really exists, and anysatisfactory theory of the causes that have led to the existingdistribution of living things, must be able to account, more orless definitely, for this and other anomalies. From these casesit will be evident, that if any class or order of animals is veryimperfectly known and its classification altogether artificial, it isuseless to attempt to account for the anomalies its distributionmay 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 ofdistribution discussed inthe preceding chapters, we should find limited and defineddistribution to be the rule, universal or indefinite distribution tobe the exception, in everynatural group corresponding to whatare usually regarded as families and genera ; and so much isthis the case in nature, that when we find a group of thisnominal rank scattered as it were at random over the earth, wehave a strong presumption that it is not natural ; but is, to aconsiderable extent, a haphazard collection of species.Of coursethis reasoning will only apply, in cases where there are nounusual means of dispersal, nor any exceptional causes whichmisht determine a scattered distribution.From the considerations now adduced it becomes evident, thatit is of the first importance for the success of our inquiry tosecure a natural classification of animals, especially as regardsthe families and genera.The higher groups, such as classes andorders, are of less importance for our purpose ; because they arealmost always widely and often universally distributed, exceptthose which are so small as to be evidently the nearly extinctrepresentatives of a once more extensive series of forms. Wenow proceed to explain the classification to be adopted, as lowdown as the series of families. To these, equivalent English