OF THE HUMAN SYSTEM. 407 



647. The organs of the external senses are gradually 

 evolved and perfected, as the external ear, the internal 

 nares, the coverings of the eyes, viz. the supra-orbital 

 arches, the eyebrows, &c. 



648. The bones of the skull unite more firmly; the 

 fonticuli are by degrees filled up ; and, about eight 

 months after birth, dentition commences. 



649. At this period the child is ready to be weaned, 

 its teeth being intended to manducate solid food and 

 not to injure the mother's breast. 



650. About the end of the first year, it learns to rest 

 upon its feet and stand erect, the highest characteristic 

 of the human body.* 



651. The child, now weaned from its mother's breast 

 and capable of using its feet, improves and acquires 

 more voluntary power daily : another grand privilege 

 of the human race is bestowed upon it, the use of 

 speech, the mind beginning to pronounce, by means of 

 the tongue, the ideas with which it is familiar. 



652. The twenty milk teeth by degrees fall out about 

 the seventh year, and a second dentition produces, in 

 the course of years, thirty-two permanent teeth. 



653. During infancy, memory is more vigorous than 

 the other faculties of the mind, and much more powerful 

 than at any other period in tenaciously receiving the 

 impressions of objects : after the fifteenth year, the fire 

 of imagination burns more strongly. 



654. This more lively state of the imagination occurs 

 very opportunely at puberty, when the body, under- 



* Ger. Vrolik (praes. Brugmans), Diss. de homine ad statum gressumque 

 *rectum per corporis fabricam disposito. Lugd. Bat. 1795. 8vo. . 



