118 



ANATOMY 



shortly after birth^ — in the cervical region of the spinal cord. 

 Myelin sheaths appear next in the cerebellum and finally in the 

 cerebrum at about 11 days. His results are given in tabular 

 form in table 79 a. It may be noted that the beginnings of 

 myelination in the cerebrum as determined histologically, coin- 

 cide with the beginning of the rapid increase in solids deter- 

 mined in other ways. 



TABLE 79a 

 Order of myelination in the nervous system of the rat — Watson ('03) 



DIVISIONS 



MYELINATION BEGINS: 



Cervi- 

 cal 

 region 



Tho- Lum- 

 racic bar 

 region region 



RAPIDITY OF 

 MYELINATION PROCESS 



Spinal cord 



Funiculus ventralis 



Funiculus lateralis 



Ventral roots 



Extra medullary. . . 



Intra medullary. . . . 

 Funiculus dorsalis 



Fasiculus cuneatus. 



Fasiculus gracilis. . 



Pyramidal tract. . . . 

 Dorsal roots 



Extra medullary. . . 



Intra medullary. • . . 



Rapid 

 Rapid 



Very rapid 

 Rapid 



Rapid 

 Slow 

 Very slow 



Slow 

 Slow 



Cerebellum 



