200 



THE REASON WHY : 



&quot; As Jacob used an ingenious invention to make Luban s 

 cattle speckled or ring-staked, so much the skill in making 

 tulips feathered and variegated, with stripes of divers colours,&quot; 



PtFttiBB. 



601. This is especially the case with our various domesticated animals ; and ther 

 are none that show it more strongly than dogs. Not only do the different races 

 of dogs vary in the colour and quantity of their hair, but also in the proportions ol 

 the different parts of their bodies, and even in their instincts. How different, fat 

 example, are the greyhound and the mastiff, 



v*. 



the bloodhound and the spaniel. We could scarcely imagine that any period of 

 time, or external influence, could ever convert one into the other. And yet they 

 had one common origin ; and it is found that their distinct forms are preserved 

 only so long as they are matched in breeds. 



Among the problems of high theoretical interest which the recent progress of 

 geology and natural history has brought into notice, no one is move prominent, 

 and, at the same time, more obscure, than that relating to the origin of species. On 

 this difficult and mysterious subject Mr. Charles Darwin has bestowed long and 

 anxious attention ; and the result of some twenty years observation and 

 experiments in zoology, botany, and geology, has established in his mind the 

 conclusion that those powers of nature which give rise to races and permanent 

 varieties in animals and plants, are the same as those which, in much longer 

 period s, produce species, and in a still longer series of ayes, give rise to difference* 

 oj generic rank,* 



602. How is the distribution of animals over the surface oj 

 the, globe accounted for f 



Several hypotheses have been set up to account for this 



Professor Lyeil* 



