142 NATURAL SELECTION VIL 
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 
