74 Wisconsin Academy of Sciences, Arts and Letters. 



TABLE XVI. 



No. of Frog 



Length of cord, mm 



Length of brachial region 

 Per cent, of total length . . 



43 



14.7 



4.8 



32.7 



The cell-bearing part of the cord, only, is measured, and 

 the table shows that the cells lie far closer in the brachial 

 region than in the succeeding cues. It is also plain that 

 there is no correspondence between the outside measure- 

 ment of diameter of cord, or of the gray matter, and the 

 number of cells contained. 



It is further noticeable that the cells are very regularly 

 distributed in the brachial region. There is a sudden rise in 

 number, a tolerably regular maintenance of a maximum, and 

 a rapid diminution at the close of the region. This fact is 

 due to the direction of exit of the fibres, it being, as before 

 said, at right angles to the cord. Part of the third ne a 

 indeed passes forward and so serves to still more clearly 

 mark the line between the first and second regions. It is 

 not easy to draw a line between the second and third re- 

 gions. In both the nerves pass off obliquely, and the roots 

 overlap each other in such a way that no sharp rise is 

 seen and no line of division can be drawn. 



The two posterior regions together contain, in percentages, 

 the following number of cells. 



TABLE XVII. 



Number of Frog. 



42 

 54.9 



In the second region it is not possible to find, in most 

 cases, enlargements corresponding to the nerves. The cells 

 are pretty evenly distributed. 



