468 NINETEENTH CENTURY. FT. m. 



ing skins would live ; and so after a time a new race of mice 

 would arise which would be independent of the cats, and the 

 bees would have a poor chance of living, and consequently 

 the flowers of bearing seeds. 



But this might in the end give rise to quite a new race 

 of plants, for it is believed that some moths would visit the 

 clovers, only, as Mr. Darwin points out, they are not heavy 

 enough to weigh down the petals of the flowers so as to 

 creep inside them. But as no two flowers are ever exactly 

 alike, it is very likely that the petals of some blossoms will 

 droop a little more than in the others, and so if the bees 

 became scarce, these blossoms with drooping petals might 

 live on, because the moths could creep into them and carry 

 their pollen from flower to flower ; and thus a new race of 

 clover with drooping petals might spring up independent of 

 the cats, the mice, and the bees, and would become a new 

 species. 



You must especially notice in this imaginary example 

 that it is only useful variations which can be passed on 

 from generation to generation. If the smell of the mice 

 (which would, probably come from some peculiarity in the 

 pores of the skin) did not preserve them from the cats, the 

 strong-smelling mice would not live, and a peculiar race 

 would not arise ; in the same way, if the drooping leaves of 

 the clover did not enable the moths to enter, those plants 

 would die out like the others. And this is one of the most 

 striking facts which Mr. Darwin has pointed out ; namely, 

 that no variation will continue and increase from generation 

 to generation unless it is useful to the plant or animal which 

 possesses it ; so that if this theory be true, every beautiful 

 colour which we admire in animals and plants, every minute 

 detail in their form and structure, is not only to be admired 

 for its beauty, but because it is an evidence of that won- 



