28 READINGS IN EVOLUTION, GENETICS, AND EUGENICS 



"The first effect of Darwin's works," says McFarland/ ''was to 

 carry the world of science by storm, but at the same time to arouse 

 intense hostihty on the part of the theologians who found the theory 

 of descent .... incompatible with the doctrines of Creation. In 

 this conflict Darwin took no part, but was championed by Huxley, 

 while Bishop Wilberforce led the opposition. The battle was long 

 and bitter, there was much acrimonious writing on both sides, but 

 the theory of descent — the doctrine of evolution — was found to be 

 invulnerable and at present the theologians themselves have accepted 

 it and even make use of it in their own work. 



" But as the years flew by the Darwinian doctrines began to meet 

 with assaults from the scientists themselves, who, having endeavored 

 to prove their validity, began to find them inadequate to the require- 

 ments of expanding knowledge. The question was asked, 'What is 

 the origin of the fittest ?' Given the fittest, we easily understand how 

 it is perpetuated, but how does it arise ? In the striking phrase of 

 someone: 'Natural selection might explain the survival of the fittest 

 but fails to account for the arrival of the fittest!' " 



Darwin's main supporters during the most trying controversial 

 period were Herbert Spencer and Thomas H. Huxley. 



Herbert Spencer (i 820-1 903) was an extremely able supporter of 

 the general theory of evolution, but was more definitely an advocate 

 of Lamarckism than of natural selection. His role was that of a 

 champion of the whole philosophy of evolution as opposed to special 

 creation, and it was largely due to his forceful writings that Darwinism 

 won the battle against dogmatism. Spencer tried to explain the 

 structure of protoplasm (living substance) on a physicochemical 

 basis. He thought of the structural units of protoplasm as compa- 

 rable with the molecules of chemical compounds, each local region 

 of the protoplasm in the organism being made up of different kinds of 

 units, which he called "physiological units. " This conception of the 

 physical basis of organic structure had a considerable influence in 

 shaping Darwin's ideas and was probably the basis of the latter's 

 provisional theory of "pangenesis." This theory was probably the 

 first consistently worked out theory of the mechanics of heredity. 

 It was thought that every part of the body is continually giving off its 

 particular kind of units ("gemmules") into the blood. These gem- 

 mules are transported by the blood stream to all parts of the body and 



^ J. McFarland, Biology, General and Medical (The Macmillan Company, 

 1918). 



