EVOLUTION. 89 



inhabitants of fresh water and, in the naturalists' esti- 

 mation, new species. 



"Professor Hooker took Alpine plants and brought 

 them to the foot of the mountain upon which he found 

 them, and, in a few years, actually succeeded in pro- 

 ducing plants which, in every respect, differed from 

 the originals, yet combining certain characters which 

 proved them identical with a species of a wholly dif- 

 ferent name and genus. By and by the naturalist 

 will be endowed with prophetic vision, as it were, and 

 be able to tell when to expect certain modifications, 

 and where to find them. 



"Now in regard to protective coloring. What is it 

 if not the way in which some animals are enabled to 

 secure their prey and to guard themselves from their 

 enemies. Look at an instance which I myself noted! 

 A troup of small fishes were quietly swimming over 

 some eel-grass when, suddenly, they took a quick turn 

 and swam off in a different direction; then, seeing before 

 them a bright, tin peach can, which had been thrown 

 into the water, they separated and instantly darted off 

 everywhere. Now what bothered me for a long time 

 was the cause of their fright at the eel-grass, and 

 it was a long time before I discovered it. By ac- 

 customing my eyes to the water, and studying it in- 

 tently for some time, I found, buried snugly in the 

 grass and of just the same color, the form of an ugly 

 old sculpin, who, as the fishes came over him, had 

 gulped down some half a dozen of them to make a 

 meal of. The sudden disappearance of so many of 

 their comrades at once, was enough to terrify the ranks 

 of any company. Of course they did not see their 

 enemy until he had made victims of some of their 

 number. Then the poor, innocent tin can must be 

 instantly avoided for its glaring colors. If that is not 

 an instance of protective coloring, what is? 



"Then, too, the practical importance of the 'sur- 

 vival of the fittest' can be illustrated in this way: Sup- 

 pose that there was but one cod fish in the word, and 

 that it produced 9,000,000 eggs. All lived, and each 



