200 



THE ANATOMT OF VERTEBRATED ANIMALS. 



The sympatlietic is well developed, except in the Ophidia, 

 where it is not distinct from the spinal nerves, in the greater 

 part of the trunk. 



««y 



Fxfl. 91. — The brains of a Lizard {Psammosnwnis Benpalenfns) and of a bird {3feteaffns 



gallopavo), in longitudinal and vertical section. Tlie upper iigure represents the liz- 

 ard's brain ; the lower (taken, like Fig. 90, B, D, from Carus's " Erlauterunga-Tafeln '') 

 that of the bird. 



The letters as in the preceding figure, except L. t, lamina terminaUs, or anterior wall 

 of the tliird ventricle ; f. M., foramen of Munro ; a., anterior commissure ; Th. E., thala- 

 moncephalon : «., soft commissure ; p., posterior commissure ; is., indicates the exact point 

 of exit of the fourth pair from that part of the brain which answers to the value of Vioussens, 



The Ojohidia, many Sauria, and Aves, possess nasal glands, 

 which, in birds, attain a large size, and lie more usually upon 

 the frontal bone, or in the orbits, than in the nasal cavity. 



The eye, rudimentary in some Ophidia and Lacertilia, is 

 usually large ; and sometimes, as in many birds and in the ex- 

 tinct Ichihyosaurla, attains very great absolute and relative 

 dimensions. 



