158 



ANATOMICAL AND PHYSIOLOGICAL STUDIES ON 



a few seconds. When six days old the rats have fairly well 

 coordinated movements. They use their fore and hind legs 

 effectively and in the same way. When the mother 's body touches 

 them they respond quickly by searching for the nipples. 



At nine days they move much more quickly and the movements 

 are well coordinated. .Though the eyes are still closed, they 



TABLE 115 



Diameters of the cells and their nuclei in the ganglion vestibulare in radial vertical section 



(Chart 43) 



crawl toward the object sought. When turned over on the back 

 they regain the normal position immediately. While resting they 

 lie on their bellies with all the legs spread well apart. 



Twelve-day-old rats, though the eyes are still closed, go to 

 and fro actively with good coordination, but are somewhat slower 

 than the adults. The body loses its fetal red color through the 

 development of the first hairs. After this period the rats do 

 not differ greatly from the adult in their general behavior. 



