The Medial Lemniscus in Lizards 
97 
MtMl 
S'^'i^Vi*; >'■’ 
Figure 5. Degeneration in tectum at level somewhat further forward to that shown in Fig. 4. 
the inferior colliculus have been demon- 
strated in the opossum (Hazlett, et al., 1972 ; 
Walsh and Ebner, 1970 ; and Robards et al., 
1974) , in the cat (Hand and Liu, 1966 ; and 
Van Noort, 1969), and in the hedgehog, tree 
shrew, African green monkey, marmoset, 
and slow loris (Schroeder and Jane, 1971). 
It is significant that, although the somato- 
sensory input is principally to the inter- 
collicular nucleus, a few fibers also appear to 
terminate in the ventrolateral region of the 
central nucleus. 
The intercollicular nucleus in poikilother- 
mic vertebrates was first seen in the tegu 
lizard (Ebbesson, 1966, 1967) during the 
tracing of ascending spinal projections. In 
this species, as well as in other reptiles 
(Ebbesson, 1969; Ebbesson and Goodman, 
1976), the nucleus is well defined by the 
degenerating spinal fibers. The afferents 
