174 THE GENESIS OF SPECIES. [CHAP. VII. 



genetic affinity, it would be rash to affirm dogmatically 

 that there is any impossibility in the independent origin 

 of such forms as ceutetes and solenodon, or of genetically 

 distinct batrachians, as similar to each other as are some 

 of the frogs of South America and of Europe. At the 

 same time, such phenomena must at present be con- 

 sidered as very improbable, from the action of ancestral 

 habit, as before stated. 



We have seen, then, that the geographical distribution 

 of animals presents difficulties, though not insuperable ones, 

 for the Darwinian hypothesis. If, however, other reasons 

 against it seem to have any weight if, especially, there 

 is reason to believe that geological time has not been 

 sufficient for it, then it will be well to bear in mind the 

 facts here enumerated. These facts, however, are not 

 opposed to the doctrine of evolution; and if it could be 

 established that closely similar forms had really arisen 

 in complete independence one of the other, they would 

 rather tend to strengthen and to support that theory. 



