512 STRUCTURE AND LIFE HISTORIES 



fear, wherever it might lead them, or however much it 

 might contradict all their prejudice and preconceived 

 notions. But truth will always, in the end, command 

 recognition and acceptance, and there is almost no scien- 

 tific man, now-a r days, who does not regard evolution as 

 axiomatic. It is one of the most basic of all conceptions, 

 not only in the natural and the physical sciences, but also 

 in history, sociology, philosophy, and religion; it has, in- 

 deed, completely revolutionized every department of 

 human thought. 



441. Darwinism. It is the second of the above men- 

 tioned theories, i.e., natural selection, that constitutes the 

 essence of Darwinism. The theory is based upon five 

 fundamental facts, which are matters of observation, and 

 may be verified by anyone, as follows : 



1. /wAm'/awce. Characteristics possessed by parents 

 tend to reappear in the next or in succeeding generations. 

 We are all familiar with the fact that children commonly 

 resemble one or both parents or a grandparent, or great 

 grandparent in some characteristic. From this we infer 

 that something has been inherited from the ancestor which 

 causes resemblance in one or more characters physical or 

 mental. 



2. Variation. But the expression of the inheritance is 

 seldom, if ever, perfect. Eyes are a little less or a little 

 more brown; stature is never just the same; one-half the 

 face may resemble a given ancestor more than another; 

 petals may be more or less red or blue; no two oranges 

 taste exactly alike; no two maple leaves are of precisely 

 the same shape. There is inheritance, but inheritance is 

 usually expressed with modifications or variations of the 

 ancestral type. 



