18 READINGS IN EVOLUTION, GENETICS, AND EUGENICS 
pleasures and pains, and many of these acquired forms or propensities 
are transmitted to their posterity.’ One could ask for no clearer 
statement of the idea that acquired characters are inherited. 
The fierceness of the struggle for existence was clearly recognized 
by Dr. Darwin. He considers that this struggle is beneficial to Nature 
as a whole because it checks the too rapid increase of life. One step 
farther in the argument, and he would have arrived at the idea of the 
survival of the fittest, but he never took that step. He agreed with 
the early Christian fathers in his belief that the powers of development 
were implanted within the first organisms by the Creator and that 
subsequent evolution of adaptive characters went on without further 
divine intervention. The power of improvement rests within the 
creature’s own organizations and is due to his own efforts. The 
effects of these efforts, he believes, are transmitted: to offspring so 
that there might be a cumulative effect throughout many generations 
of the results of effort. 
Erasmus Darwin was perhaps the first to express clearly the ideas 
that millions of years have been required for the processes of organic 
evolution and that all life arose from one primordial protoplasmic 
mass. He writes as follows: 
“From thus meditating upon the minute portion of time in which 
many of the above changes have been produced, would it be too bold 
to imagine, in the great length of time since the earth began to exist, 
perhaps millions of ages before the commencement of the history of 
mankind, that all warm-blooded animals have arisen from one living 
filament, which the first great Cause imbued with animality, with the 
power of acquiring new parts, attended with new propensities, directed 
by irritations, sensations, volitions, and associations, and thus possess- 
ing the faculty of‘continuing to improve by its own inherent activity, 
and of delivering down these improvements by generation to pos- 
terity, world without end?” 
LAMARCK 
Lamarck (1744-1829), the greatest of French evolutionists, is now 
looked upon as “the founder of the complete modern Theory of 
Descent.”” Osborn considers him “the most prominent figure between 
Aristotle and Darwin. One cannot compare his Philosophie zoblogique 
with all previous and contemporary contributions to the evolution 
theory or learn the extraordinary difficulties under which he laboured, 
and that his work was put forth only a few years after he had turned 
