Variations in Spinal Nerves of Hyla aurea. 277 



nerve X. (6), than does nerve VIII., thickness 3. We may thus 

 say that there is a tendency for VIII. to increase in thickness as 

 X. decreases. 



16. As X. diminishes, IV. may diminish also. Again we 

 find great irregularities. The maximum frequency of nerve IV., 

 thickness 4, independently of single occurrences, is found with 

 thickness 9, of nerve X., while that of nerve IV., thickness 3, is 

 found with nerve X., thickness 7. On the other hand nerve IV., 

 thickness 2 occurs only with nerve X., thickness 9, and nerve 

 IV., thickness 6, only with nerve X., thickness 8. 



17. If we examine first the smaller thicknesses 10 to 12, of 

 nerve III., we find a tendency for nerve III. to decrease in 

 thickness with a decreasing thickness of X. But thicknesses 13 

 and 14, of nerve III., appear to directly oppose this, since their 

 maxima of frequency occur with the lower thicknesses of nerve 

 X. On the other hand, however, the table as a whole (exclusive 

 of thickness 19, of nerve III.), would appear to show a decrease 

 in nerve III. with a decrease in nerve X. 



18. As X. decreases. II. decreases also. The frequency of 

 thicknesses 3 and 4, of nerve II., seem to point to a decreasing 

 thickness of nerve II., corresponding to a falling thickness of 

 nerve X. 



19. While IX. increases, VIII. increases also. The relations 

 between these two nerves are very indefinite, but there is 

 evidently a tendency for an increase in thickness of nerve VIII. 

 to accompany an increasing thickness of nerve IX., as seen in 

 the position of the maxima of frequency of thicknesses 4, 5, and 6 

 of nerve VIII., with thicknesses 7, 10, and 10 of nerve IX. 



20. While IX. increases, IV. increases also. The frequency 

 of nerve IV., thickness 3, reaches a maximum with nerve IX., 

 thickness 1 ; nerve IV., thickness 4, with nerve IX., thickness 9; 

 and nerve IV., thickness 5, with nerve IX., thickness 11 ; while 

 nerve IV., thickness 2, is found with nerve IX., thickness 8, and 

 nerve IV., thickness 6, with nerve IX., thickness 11. 



21. While IX. increases, III. increases also. The lowest 

 thicknesses, 7 and 9, and highest, 11 to 19, of nerve III., bear 

 evidence rather in favour of this statement, while the frequency 

 of the intermediate thicknesses of nerve III., i.e., 10, 11, 12 and 

 13, reach their maxima with nerve IX., thicknesses 7, 9, 10 and 

 11 respectively. 



