24 EVOLUTION. 



arisen from common stocks by perpetual changes, 

 such as were required to adapt them to their sur- 

 roundings, then there would result these variously 

 modified forms, retaining traces of the characters of 

 ancestral races. 



Evolution, therefore, shows that animals of each 

 type resemble each other because they have a com- 

 mon ancestry. Descent ivith modification is a phrase 

 that explains the existing facts. All the allied forms 

 have had a common origin, but have developed dif- 

 ferent peculiarities in consequence of having been 

 placed in differing circumstances. When a variation 

 of an organ occurred that was of advantage it was 

 perpetuated by natural selection. 



The resemblance of man to animals is not only 

 observed as to structure, but many peculiarities are 

 possessed in common. Parasites infest their bodies, 

 their functions follow lunar periods, the same diseases 

 afflict them, and can be transmitted from one to the 

 other — colds, inflammations, fevers, apoplexy, etc., as- 

 sail each. Drugs affect both alike, — opium, quinine, 

 tobacco, alcohol, all produce similar results in each 

 and prove a likeness of constitution. Their wounds 

 heal by the same process. The laws of reproduction 

 are, in Darwin's words, " strikingly the same, from 

 the first act of courtship of the male to the birth and 

 maturing of the young." The mental powers and 

 moral sense are of the same character, only differing 

 in degree, and the manner of expressing emotions is 

 in many respects similar among men and beasts. 



