328 HUMAN PHYSIOLOGY 



preparation) must be regarded as makeshifts and are often 

 not suited for the child. The average amount of milk which 

 the infant takes is as follows: During first day 30 grams, 

 second day 150, third day 400, fourth day 550 grams; after 

 one month 650, three months 750, four months 850, six to 

 nine months 950 grams. 



The length of the body of the child at birth is about 

 50 cm. 



The infant grows during the first month 4 cm, during the 

 second month 3 cm, during the third month 2 cm, and 

 during the following months 1 1.5 cm - The total increase 

 in length during the first year is about 2O cm, during the 

 second year 9 cm, and during the third year 7 cm. The 

 weight after birth is 3 kg. Immediately after birth the infant 

 loses from 100300 grams of its body \veight. After this its 

 weight increases and after the tenth day it has regained its 

 previous weight. During the first five months the weight 

 of the normally nourished child increases on the average 20 

 to 30 grams daily; during the next seven months 10-15 

 grams daily. After one year the child weighs about 9 kg. 



During the first days after birth the child discharges the 

 mcconium through the anus. Later on the stools of the 

 normally fed child are yellowish and of medium consistency. 



(c) The nervous system and the senses of the infant. 

 Concerning the physiological development of the central 

 nervous system during infancy the following maybe said: 

 At birth certain reflex and coordinated movements, those 

 necessary for the maintenance of life (respiration movements, 

 sucking, deglutition) are present. Sucking takes place 

 reflexly when a foreign body touches the lips. The coordi 

 nated movements which play a part in standing and walking 

 are not present in the human infant immediately after birth, 

 but are learned during the first or second year. This is also 

 true for the coordinated movements for speech. The reflex- 

 irritability is greater in the infant than in the adult. Reflex 

 cramps can be produced by relatively feeble stimulation of 

 sensory nerves (e.g. convulsions during dentition, tetanus). 



