142 NATURAL SELECTION vn 



supervision and direct interference of the Creator, and 

 cannot possibly be explained by the unassisted action of any 

 combination of laws. Now, Mr. Darwin's work has for its 

 main object to show that all the phenomena of living things, 



all their wonderful organs and complicated structures, their 



infinite variety of form, size, and colour, their intricate and 

 involved relations to each other, may have been produced 

 by the action of a few general laws of the simplest kind, laws 

 which are in most cases mere statements of admitted facts. 

 The chief of these laws or facts are the following : 



1. The Law of Multiplication in Geometrical Progression. 

 All organised beings have enormous powers of multiplication. 

 Even man, who increases slower than all other animals, could 

 under the most favourable circumstances double his numbers 

 every fifteen years, or a hundredfold in a century. Many 

 animals and plants could increase their numbers from ten to 

 a thousandfold every year. 



2. The Law of Limited Populations. The number of living 

 individuals of each species in any country, or in the whole 

 globe, is practically stationary; whence it follows that the 

 whole of this enormous increase must die off almost as fast 

 as produced, except only those individuals for whom room is 

 made by the death of parents. As a simple but striking 

 example, take an oak forest. Every oak will drop annually 

 many thousands of acorns, but till an old tree falls not one 

 of the millions of acorns produced can grow up into an oak. 

 They must die at various stages of growth. 



3. The Law of Heredity, or Likeness of Offspring to their 

 Parents. This is a universal, but not an absolute law. All 

 creatures resemble their parents in a high degree, and in the 

 majority of cases very accurately; so that even individual 

 peculiarities, of whatever kind, in the parents, are almost 

 always transmitted to some of the offspring. 



4. The Law of Variation. This is fully expressed by the 

 lines : 



" No being on this earthly ball, 

 Is like another, all in all. " 



Offspring resemble their parents very much, but not wholly 

 -each being possesses its individuality. This " variation " 

 itself varies in amount, but it is always present, not only in 



