260 



THE ANATOMY 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. 



Fig. 91. — The brains of a Lizard {Psammosatvrus Benftalenfds) and of a bird {Meleagrii^ 

 gallopavo), in longitudinal and vertical section. The upper figure represents the liz- 

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

 that of the bird. 



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

 of the third ventricle;/. J/., foramen of Munro; a., anterior commissure; Th. ^., thala- 

 mcncephalon ; s., soft commissm-e ; /)., posterior commissure ; iv., indicates the exact point 

 of exit of the fourth pair from that part of the brain which answers to the value of Vieussens. 



The Ophtdla, 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 Opliidia and Lacertilia, is 

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

 tinct Ichthyosauria^ attains Yerj great absolute and relative 

 dimensions. 



