4 READINGS IN EVOLUTION, GENETICS, AND EUGENICS 



"It is interesting to contemplate a tangled bank, clothed with 

 many plants of many kinds, with birds singing on the bushes, with 

 various insects flitting about, and with worms crawling through the 

 damp earth, and to reflect that these elaborately constructed forms, 

 so different from each other, and dependent upon each other in so com- 

 plex a manner, have all been produced by laws acting around us. 

 These laws, taken in the largest sense, being Growth with Reproduc- 

 tion ; Inheritance which is almost implied by reproduction ; Variability 

 from the indirect and direct action of the condition of life, and 

 from use and disuse ; a Ratio of Increase so high as to lead to a struggle 

 for Life, and as a consequence to Natural Selection, entailing Diver- 

 gence of Character and the Extinction of less-improved forms. Thus, 

 from the war of nature, from famine and death, the most exalted 

 object which we are capable of conceiving, namely, the production of 

 the higher animals, directly follows. There is a grandeur in this view 

 of life, with its several powers, having been originally breathed by the 

 Creator into a few forms or into one; and that, while this planet has 

 gone cycling on according to the fixed law of gravity, from so simple a 

 beginning endless forms most beautiful and most wonderful have been, 

 and are being evolved. " — Charles Darwin, Origin of Species, conclud- 

 ing paragraph. 



" Speaking broadly we find as a fact that transmutation of species 

 through the geologic ages has been accompanied by increasing diver- 

 gence of type, by the increased specialization of certain forms, and by 

 the closer and closer adaptation to conditions of life on the part of the 

 forms most highly specialized, the more perfect adaptation and the 

 more elaborate specialization being associated with the greatest 

 variety or variation in the environment. Accepting for this process 

 the name organic evolution, Herbert Spencer has deduced from it the 

 general law, that as life endures generation after generation, its 

 character, as shown in structure and function, undergoes constant 

 differentiation and specialization. In this view, the transmutation 

 of species is not merely an observed process, but a primitive necessity 

 involved in the very organization of life itself." — D. S. Jordan and 

 V. L. Kellogg, Evolution and Animal Life (1908), p. 4. 



"The Doctrine of Evolution is a body of principles and facts con- 

 cerning the present condition and past history of the living and lifeless 

 things that make up the universe. It teaches that natural processes 



