vi TABLE OF CONTENTS 



CHAPTEK IV 



PAGE 



VERTEBRATES : BACKBONE AND BRAIN 81 



The advance of vertebrates from fish through amphibia and reptiles to 

 mammals. The development of skeleton, appendages, circulatory and 

 respiratory systems, and brain. Mammals : The oviparous monotremata. 

 Marsupials. Placental mammals. Development of the placenta. Prim- 

 ates. Arboreal life and the development of the hand. Comparison of man 

 with the highest apes. Recapitulation of the history of man's origin and 

 development. The sequence of dominant functions. 



CHAPTEE V 



THE HISTORY OF MENTAL DEVELOPMENT AND ITS 

 SEQUENCE OF FUNCTIONS 113 



Mode of investigation. Intellect. Sense-perceptions. Association. - 

 Inference and understanding. Rational intelligence. Modes of mental or 

 nervous action. Reflex action, unconscious and comparatively mechanical. 

 Instinctive action : The actor is conscious, but guided by heredity. In- 

 telligent action. The actor is conscious, guided by intelligence resulting 

 from experience or observation. The will stimulated by motives. Appe- 

 tites. Fear and other prudential considerations. Care for young and love 

 of mates. The dawn of unselfishness. Motives furnished by the rational 

 intelligence : Truth, right, duty. Recapitulation : The will, stimulated by 

 ever higher motives, is finally to be dominated by unselfishness and love 

 of truth and righteousness. These rouse the only inappeasable hunger, 

 and are capable of indefinite development. Strength of these motives. 

 Their complete dominance the goal of human development. 



CHAPTER VI 



NATURAL SELECTION AND ENVIRONMENT . . . .152 



The reversal of the sequence of functions leads to extermination, degen- 

 eration, or, rarely, to stagnation. Natural selection becomes more un- 

 sparing as we go higher. Extinction. Severity of the struggle for life. 

 Environment one. But lower animals come into vital relation with but a 

 small part of it. It consists of a myriad of forces, which, as acting on a 



