THE DARWINIAN THEORY. 



95 



provement. Let this process," says Darwin, " go on for millions 

 and millions of years, and during each year on millions of indi- 

 viduals of many kinds ; may we not believe that a living optical 

 instrument might be thus formed as superior to one of glass as 

 the works of the Creator are to those of man ? " 



His opponents instance the case of the Trilobites, which 

 occur in the lowest fossiliferous rocks, and show how complex 

 their eyes are (each having from four hundred to six thousand 

 facets), while the time for developing these intricate organs is 

 supposed to be limited. [Now, however, this time has been 

 greatly extended, even to five hundred millions of years as the 

 age of the earth.] 



Darwin observes that where the habits and structure of an 

 animal are not in agreement, the apparent anomaly can only be 

 explained by its struggle for existence, it having been beaten off 

 its natural ground and forced to seek subsistence elsewhere. 

 Thus it is why Grebes, Coots, and Waterhens, all eminently 

 aquatic in their habits, have imperfectly webbed feet — indeed, 

 the latter not at all ; why the Landrail which closely resembles 

 the Waterhen is almost as terrestrial as the Partridge. So when 

 winter shuts out with its barriers of ice the Mustela vison (an 

 animal much resembling an Otter), which all summer has 

 preyed on fish by diving, it leaves the frozen water in its struggle 

 for existence and preys, like a Polecat, on mice and land 

 animals.* 



Darwin cautions his objectors as to the fallacy of rashly con- 

 cluding that this or that organ could not have been formed by 

 transitional gradations of some kind, and adduces in support of 

 his position the fact that the alimentary canal of the larva of 

 the dragonfly and the fish Cobites (a kind of Loach) acts the part 

 of a lung, stomach, and intestines. The Common Hydra may 

 be turned inside out, and what before acted as skin now acts as 

 stomach and the stomach acts as skin.t Again, it might be 



* Change of habits is seen also in the Tyrant Flycatcher, hovering like a 

 hawk and plunging into water for fishes ; in the Black Bear, swimming on the 

 surface of the water with widely open mouth catching insects like a Whale ; 

 and in the case of Baker and his Germau's Donkey, which, when hunting in 

 the Base Country, fed on the flesh of Antelopes, and throve exceedingly. In 

 the same way the Zetlandic cattle acquire a fondness for dried fishes. 



f This is now interpreted differently. 



