246 READINGS IN BIOLOGICAL SCIENCE 



to be. One group, the primates, came in for a special education of body 

 and brain that had a more direct human trend. The early anthropoids, 

 man's line, were tree-dwellers. Toward the middle of the Cenozoic our 

 direct progenitors came down out of the trees, adapted themselves to the 

 ground, spread beyond the forest, and assumed an increasingly erect 

 posture. 



The Cenozoic was sixty million years long. Its last division, the Pleisto- 

 cene or Glacial, was one million. Through this past period, which includes 

 four glacial stages with long intervening interglacial epochs, man was 

 slowly straightening up, increasing in brain capacity and intelligence, de- 

 veloping speech, inventing tools. His prolongation of infancy, far beyond 

 that of other mammals, carried with it increasing teachableness, and the 

 lengthening of the period in which offspring were dependent on their 

 parents led to the beginning of the family with its accompanying in- 

 tensification of the altruistic sentiments, to the growth of the qualities 

 which we consider most distinctively human. 



Early in the Pleistocene, forms recognized as man and not ape are 

 found (Java, Peking and Piltdown man). Neanderthal man {Homo 

 ?ieanderthalensis) made his appearance in the last interglacial epoch; but 

 it was not until the last glacial epoch, perhaps 50,000 years ago, that Cro- 

 Magnon man appeared in western Europe, the first that is admitted to the 

 present species {Homo sapiens), and whose descendants are doubtless 

 with us to-day. Erect, with prominent chin, high forehead and brain as 

 large as that of modern man, he was skilled in the use of simple tools, and 

 his carvings and drawings and polychrome paintings are the admiration of 

 anthropologists. Cro-Alagnon man stands at a pivotal point in the world's 

 history. He is the climax of two billion years of animal evolution. Man's 

 long preliminary education is now completed. The stage is set for a new 

 act in the drama of life; whether comedy or tragedy we do not yet know. 



The purpose of this emphasis on the length of life on the earth is to 

 show that the race enters manhood with an immense animal momentum. 

 The Roman Catholic Church is said to hold that if it can have the teach- 

 ing of its youth for the first seven years, it will guarantee them to the 

 Church for life. Nature is man's teacher, and she has had his early educa- 

 tion for a vastly longer time proportionally than the Catholic Church asks 

 for its youth. Man has been in the distinctively human school less than 

 a million years. He was in the primate (not primary) division throughout 

 the Cenozoic, sixty times as long. He began his primary education as some 

 single-celled form in the early pre-Cambrian ocean, possibly two thousand 

 times as far back as the day when he was promoted to the human grade. 

 Nature has insured that he learn his lesson well; that the animal is so in- 

 wrought in him that he can never get away from it. His human nature is 

 a recently acquired and uncomfortably-worn garment. 



