Ingbert, Ventral Roots of Spinal Nerves. 211 



of a man to be (when corrected by adding .2 mm.^) 34.51 mm^ 

 2. Stilling' s Determination. — In the paper just referred to 

 (Ingbert, June, 1903, p. 55) the details of the conditions un- 

 der which Stilling (1859, P- 34^) rnade his measurements are 

 also given. His determination for the total area of all the ven- 

 tral roots of the left spinal nerves in a woman was 35.23 mm^. 

 ^. Authors Determination. — Using a method similar to 

 that employed in the measuring of the areas of the dorsal roots 

 (Ingbert, June, 1903, p. 56), it was found that the total area of 

 the ventral roots of the left spinal nerves of the same individual 

 amounted to 26.50 mm^. 



^. Comparison of Areas. — The total areas of the cross- 

 sections of the ventral roots of the left spinal nerves obtained 

 by the preceding investigations are as follows : 



KoLLlKER (male) 34-51 mm'^ 



^ Stilling (female) 35.23 mm'' 



Author's Case (male) 26.50 mm''' 



As the case here presented shows a smaller area than that 

 found by either Kollikek or Stilling some comment is called 

 for. It may be stated at the outset that the areas for the ven- 

 tral roots in the author's case were measured in 365 distinct 

 fascicles ; that, further, from the total area first determined in 

 this way there was ultimately subtracted 1.54 mm^, represent- 

 ing the excess of area caused by fascicles cut obliquely. In 

 the case of Kolliker's measurements it is readily seen why 

 they should be large, since he included all the connective tissue 

 within the roots in his determination. For example, when the 

 roots in the author's case were measured by the method of 

 Kolliker they gave an area of 40.81 mm^. This not only 

 shows why Kolliker's area is large but also indicates that in 

 the particular spinal cord the roots of which he measured, the 

 roots themselves were rather small. This conclusion is sup- 

 ported by the fact that Stilling, in the case of a woman, found 

 the area of the left ventral roots to be 35.23 mm^ Yet Stilling 

 measured the roots in fascicles, by means of a planimeter, and 

 thus included much less connective tissue than Kolliker. That 

 Stilling's result is larger than that of the author might be ex- 



