146 THE HISTORY OF CREATION. 



exists this difference, that the former are capable of pro- 

 ducing fruitful bastards, but that the latter are not. Two 

 different cultivated races, or wild varieties of one species, 

 are said in all cases to possess the power of producing 

 bastards which can fruitfully mix with one another, or 

 with one of their parent forms, and thus propagate them- 

 selves ; on the other hand, two really different species, two 

 cultivated or wild species of one genus, are said never to be 

 able to produce from one another bastards which can be 

 fruitfully crossed with one another, or with one of their 

 parent species. 



As regards the first of these assertions, it is simply re- 

 futed by the fact that there are organisms which do not 

 mix at all with their own ancestors, and therefore can 

 produce no fruitful descendants. Thus, for example, our 

 cultivated guinea-pig does not bear with its wild Brazilian 

 ancestor ; and again, the domestic cat of Paraguay, which is 

 descended from our European domestic cat, no longer bears 

 with the latter. Between different races of our domestic 

 dogs, for example, between the large Newfoundland dogs 

 and the dwarfed lap-dogs, breeding is impossible, even for 

 simple mechanical reasons. A particularly interesting in- 

 stance is afforded by the Porto-Santo rabbit (Lepus Hux- 

 leyi). In the year 1419, a few rabbits, born on board 

 ship of a tame Spanish rabbit, were put on the island of 

 Porto Santo, near Madeira. These little animals, there 

 being no beasts of prey, in a short time increased so enor- 

 mously that they became a pest to the country, and even 

 compelled a colony to remove from the island. They still 

 inhabit the island in great numbers ; but in the course of 

 four hundred and fifty years they have developed into a quite 



