Variation* in Spinal Nerves of Hyla aurea. 271 



13 h S 6 J 8 f lo It 1% 15 fU /5~ t6 /y /? /? 



Fi*. A 



So far as I am able to judge from the data given by Adolphi, 

 the numbers thus arrived at should be quite comparable with his. 



I have examined 125 specimens of Hyla aurea, and instead of 

 regarding, as Adolphi has done, each specimen as yielding two 

 separate observations, one for each side, I have considered it as 

 one observation, or where the two sides differ from one another 

 as two half observations. This does not interfere with the 

 comparison of the two sets of tables, as the percentage relations 

 are not affected thereby. The following results are brought 

 together in Table A.* 



Nerve XII., as I have mentioned above, was found in 3'2 per 

 cent, of all cases — of these 2*4 per cent, had thickness 1, and # 8 

 per cent, thickness 2. 



Nerve XL varies in thickness from 1 to 6 — The majority of 

 cases, 88 - 8 per cent, were divided between thicknesses 2 and 3, 

 the former having 46*4 per cent., the latter 42-4 per cent. 

 Thickness 4 and over occur but seldom. This nerve was 

 present in every case, as constrasted with Bufo variabilis.^ 



In Nerve X. we find a wide range of thickness, viz., from 3 to 

 12. The majority, 82-4 per cent, are found among thicknesses 

 7 to 10. Thicknesses 4 to 6 are seldom seen, and 3, 11, and 12 

 very seldom. 



* All Tables referred to are placed at the end of the memoir. 

 t hoc. cit., 1893, p. 321. 



