Forebrain and Midbrain of Lizards 
17 
vm 
Figure 3. Transverse sections through rostral (A) and caudal (B) levels of the right telencephalic hemis- 
phere of the green iguana, Iguana iguana, stained to demonstrate neuron cell bodies. Bar scale represents 
1 mm. A-D, sensory zones of the anterior division of the dorsal ventricular ridge; cd, (Cl-3), dorsal cortex 
and its subdivisions; cl, lateral cortex; cm (Cl-2), medial cortex and its dorsal (Cl) and ventral (C2) 
subdivisions; dvr,p, posterior division of the dorsal ventricular ridge, na, nucleus accumbens; not, nucleus of 
the lateral olfactory tract; ns, nucleus sphericus; ot, olfactory tubercle; s, septal nuclei; st, striatum; vm, 
nucleus ventromedialis. 
medial cortex in Chrysemys. These fibers 
appear to originate in the hypothalamus and 
tegmentum, and similar pathways have been 
reported in amphibians and mammals 
(Hedreen, 1971; Northcutt, 1972, 1974; 
Kicliter and Northcutt, 1975). Thus, it ap- 
pears likely that lizards also possess an 
ascending monoamine pathway to the medial 
cortex, and it is possible that large lesions 
of the thalamus may have interrupted such 
