The Motor GaiujJion Cells of tlie Frog's Spinal Cord. 65 



The addition of all the cells gives 5,777 for the right side 

 5,740 for the left side, as in table I. It will be seen that the 

 numbers in the same section usually differ and often con- 

 siderably, while each group of five sections or one-tenth 

 mm. shows a closer corrrespondence. 



The total number of the cells varies in proportion to the 

 weight of the frog as shown by 



