THE HEALTHY INFANT. 243 



chap. ii. p. 13). The infant is said not to show actual 

 signs of mind, though it may show potentialities. 

 The infant does not walk, talk, or turn its eyes 

 and head towards a bright object within its field 

 of vision ; its movements are not modified in any 

 marked degree by the action of light or sound, 

 except that the orbiculares oculi contract spasmodi- 

 cally to light. The infant is less impressionable, 

 and the impressions produced by light, etc., are less 

 permanent than in the adult. 



Again, to speak of infant development, the signs 

 of its brain development are identical with the 

 signs of its mental development. Speaking of 

 either mode of development in an infant we may 

 give its expression. 



The healthy infant born at full time weighs 

 between six and ten pounds ; its limbs and members 

 are complete in all parts fingers, toes, nails, etc. 

 The head measures in circumference from eleven to 

 twelve inches ; the sutures or junctions of the bones 

 of the vault of the skull are not closed or ossified, 

 and the anterior fontanelle is open. We may also 

 observe the form, size, and proportions of the body, 

 and particularly of the head, as signs which indicate 

 to some extent the degree and condition of brain 

 development. 



Respiratory movements in the infant are estab- 

 lished at birth, and continue without interruption ; 

 the child cries when its skin is cold or wet, and 

 when the stomach has been empty more than two; 

 hours. 



The nerve-muscular mechanism and the sensory 



