WHAT IS DARWINISM? 29 



enormously the means of support. If all the 

 seeds of a plant, all the spawn of a fish, were 

 to arrive at maturity, in a very short time the 

 world could not contain them. Hence of ne- 

 cessity arises a struggle for life. Only a few 

 of the myriads born can possibly live. 



Fourth, here comes in the law of Natural 

 Selection, or the Survival of the Fittest. That 

 is, if any individual of a given species of plant 

 or animal happens to have a slight deviation 

 from the normal type, favorable to its success in 

 the struggle for life, it will survive. This vari- 

 ation, by the law of heredity, will be trans- 

 mitted to its offspring, and by them again to 

 theirs. Soon these favored ones gain the 

 ascendency, and the less favored perish ; and 

 the modification becomes established in the 

 species. After a time another and another of 

 such favorable variations occur, with like re- 

 sults. Thus very gradually, great changes of 

 structure are introduced, and not only species, 

 but genera, families, and orders in the vegeta- 

 ble and animal world, are produced. Mr. Dar- 

 win says he can set no limit to the changes of 

 structure, habits, instincts, and intelligence, 

 which these simple laws in the course of mil- 

 lions or milliards of centuries may bring into 



