130 



COMPARATIVE ANATOMY. 



FIG. 104. THE ENTIRE NERVOUS SYSTEM OF THE FROG. (After A. Eckr.) 



(From the ventral side. ) 



He, cerebral hemispheres (prosencephalon) ; Lop, optic lobes (mesencephalon) ; J)/, 

 spinal cord ; Ml to M10, spinal nerves, which are connected at 8M by branches 

 (rami communicantes) with the ganglia (SI to 810) of the sympathetic (8) ; No, 

 iemoral'nerve ; Ni, sciatic nerve ; / to X, first to tenth cranial nerves (for their 

 names, see text) ; G, ganglia of the vagus ; Vg, Gasserian ganglion ; o, eye ; N, 

 nasal sac ; Va to Vc t the different branches or the trigemiual ; F, facial nerve ; 

 Vs, connection of the sympathetic with the Gasserian ganglion ; XI to X4, the 

 different branches of the vagus. Some of the fibres of the sympathetic should 

 be shown accompanying the vagus peripherally. 



