16 READINGS IN EVOLUTION, GENETICS, AND EUGENICS 
general ideas of evolution were comprehensive and summed up the 
best features of all preceding writers, but he did not contribute any- 
thing new to the pressing problem of the causes of evolution. 
Real progress was not to be ‘made through further speculation. 
What was most needed was facts, and it was the task of the naturalists 
to furnish these. The earliest of the eighteenth-century naturalists 
were still anticipators of Nature in that their theories outran their 
facts. Of these the names of Bonnet and Oken are the best known. 
Bonnet (1720-93) was an evolutionist only in the sense that he 
believed that the adult organism is present in the egg and evolves from 
it by a process of unfolding or expansion. He was a zodlogical 
observer of some note, however, and made some of the most important 
contributions of his time to the general subject. He believed ‘that 
the globe had been the scene of great revolutions, and that the chaos 
described by Moses was the closing chapter of one of these; thus the 
Creation described in Genesis may be only a resurrection of animals 
previously existing.”” This theory admits of no progress and is 
scarcely worthy of the name evolution. 
Oken (1776-1851) is known chiefly for his “Urschleim’’ doctrine 
and his ideas of cells as vesicular units of life. According to him, 
“‘Every organic thing has arisen out of slime and is nothing but slime 
in various forms. This primitive slime originated in the sea from 
inorganic matter.” These ideas are purely speculative, but suggest 
our modern ideas of protoplasm and cells. 
THE GREAT NATURALISTS OF THE EIGHTEENTH CENTURY 
Three great names stand out above all the rest during this period: 
those of Linnaeus, Buffon, and Erasmus Darwin. 
Linnaeus (1707-78) was the father of taxonomy. He contributed 
facts rather than theories; he invented our present system of binomial 
nomenclature of both animals and plants, and a great many of his 
generic and specific names ‘still persist. Unfortunately he was an 
ardent advocate of the special-creation idea, holding that all of the 
true species were created as they are known today, except that new 
combinations may have arisen through hybridization or through 
degeneration. His influence was great, but was reactionary and proved 
a serious hindrance to the progress of the evolution idea. 
Buffon (1707-88), born the same year as Linnaeus, has been 
recognized as the father of the modern applied form of the evolution 
idea. He attempted to explain particular cases on an evolutionary 
