368 MAN --AN ADAPTIVE MECHANISM 



mother lacks salt or certain vegetables and scurvy 

 appears, the offspring suffers also. Thus, the simplest 

 mechanistic causes may terminate the life of the fetus 

 or produce a weak or defective child. 



The first respiratory movements of the newborn 

 babe are excited by the very delicately adjusted center 

 in the medulla which responds to external stimuli or 

 to slight variations in the alkalinity (H-ion concentra- 

 tion) of the blood, this variation being produced by the 

 asphyxia resulting from the withdrawal of the maternal 

 circulation when the placental structures are separated. 

 With the pressure of the lips of the newborn child 

 against the nipple, the act of sucking is excited. The 

 presence of milk in his mouth excites swallowing ; and 

 the entire digestive mechanism is activated by the 

 swallowed milk. Thus the child becomes a breathing, 

 sucking, digesting mechanism. Light and shadow and 

 sound soon activate his brain. Each activation of the 

 mechanism for the execution of a given action through 

 contact or distance stimuli facilitates the passage of 

 repetitions of these stimuli, and thus are the first of 

 the vast numbers of action patterns formed. In the 

 plastic brain of the newborn babe new action patterns 

 are made during each wakeful moment. Contact 

 stimuli become associated with distance stimuli and 

 associative memory is established. 



That the standard of chemical purity in the body 

 may be maintained, the organs of the kinetic system 

 are stimulated to increased activity by the presence of 

 foreign proteins. In like manner, hunger, thirst and 

 cold stimulate the kinetic system to activities by which 

 food, drink and shelter may be secured. Threatened 



