The Medial Lemniscus in Lizards 
103 
ACKNOWLEDGMENTS 
This work was supported by NIH Career Develop- 
ment Award NS46292, NIH Grant EY00154, and 
NASA Grant NGR47-005-186. Ms. Lolyn Lopez and 
Ms. Linda Van der Linde prepared the histologic 
specimens for this study, and Dr. Hans Distel as- 
sisted with surgery and perfusion of the animals. 
REFERENCES 
Ariens Kappers, C.U., G.C. Huber, and E.C. Crosby. 
1936; 1967. The comparative anatomy of the 
nervous system of vertebrates including man. 
Macmillian, New York; Hafner, New York. 
Belekhova, M.G., and A.A. Kosareva. 1971. Organi- 
zation of the turtle thalamus: Visual, somatic and 
tectal zones. Brain, Behav. Evol. 4:337-375. 
Berman, A.L. 1968. The brain stem of the cat. Univ. 
Wisconsin Press, Madison. 
Boesten, A.J.P. 1971. Systemes afferents et ultra- 
structure de la parolive externe chez le chat. Comp. 
Rend. Ass. Anat. 152:459-465. 
Boesten, A.J.P., and J. Voogd. 1975. Projections of 
the dorsal column nuclei and the spinal cord on the 
inferior olive in the cat. J. Comp. Neur. 161:215- 
238. 
Christensen, K. 1917. The Morphology of the Brain 
of Sphenodon. Univ. of Iowa Studies in Natural 
Hist., 12. 
Ebbesson, S.O.E. 1966. Ascending fiber projections 
from the spinal cord in the tegu lizard, Tupin- 
ambis nigropunctatus. Anat. Rec. 154:341-342. 
Ebbesson, S.O.E. 1967. Ascending axon degeneration 
following hemisection of the spinal cord in the 
tegu lizard, Tupinambis nigropunctatus. Brain 
Res. 5:178-206. 
Ebbesson, S.O.E. 1968. A connection between the 
dorsal column nuclei and the dorsal accessory olive. 
Brain Res. 8:393-397. 
Ebbesson, S.O.E. 1969. Brain stem afferents from the 
spinal cord in a sample of reptilian and amphibian 
species. Ann. N.Y. Acad. Sci. 167:80-101. 
Ebbesson, S.O.E. 1970a. The selective silver-impreg- 
nation of degenerating axons and their synaptic 
endings in nonmammalian species. In Nauta, W. 
and Ebbesson, S.O.E. (eds.). Contemporary Re- 
search Methods in Neuroanatomy, pp. 132-161. 
Springer-Verlag, New York. 1970. 
Ebbesson, S.O.E. 19706. On the organization of cen- 
tral visual pathways in vertebrates. Brain, Behav. 
Evol. 3:178-194. 
Ebbesson, S.O.E. 1972. New insights into the organi- 
zation of the shark brain. Presented at the Elasmo- 
branch Biology Symposium, June 1971. Comp. Bio- 
chem. and Physiol. 42:121-129. 
Ebbesson, S.O.E. 1976. Organization of the ranid 
spinal cord. In Llinas and Precht, (Eds.) Neuro- 
biology of the Frog. Springer, New York. 
Ebbesson, S.O.E., and D.C. Goodman. The organiza- 
tion and ascending spinal projections in reptiles 
In C. Gans (ed.) Biology of the reptilia. Academic 
Press, New York, in press. 
Ebbesson, S.O.E., and K. Rubinson. 1971. Macro- 
photography of histological sections. Physiol. 
Behav. 7: 261-262. 
Fernstrom, R.C. 1958. A durable Nissl stain for 
frozen and paraffin sections. Stain Technol. 33: 
175-176. 
Fink, R.P. and L. Heimer. 1957. Two methods for 
selective silver impregnation of degenerating axons 
and their synaptic endings in the central nervous 
system. Brain Res. 4:369-374. 
Goldberg, J.M. and R.Y. Moore. 1967. Ascending 
projections of the lateral lemniscus in the cat and 
monkey. J. Comp. Neur. 129:143-156. 
Goldby, F., and L.R. Robinson. 1962. The central 
connections of dorsal spinal nerve roots and the 
ascending tracts in the spinal cord of Lacerta 
viridis. J. Anat. 96:153-170. 
Groenewegen, H.J., A.J.P. Boesten, and J. Voogd. 
1975. The dorsal column nuclear projections to the 
nucleus ventralis posterior lateralis thalami and 
the inferior olive in the cat: An autoradiographic 
study. J. Comp. Neur. 1962:505-518. 
Hand, P.J., and C.M. Liu. 1966. Efferent projection 
of the nucleus gracilis. Anat. Rec. 154:353—354. 
Hazlett, J.C., R. Dom, and G.F. Martin. 1972. Spino- 
bulbar, spino-thalamic and medial lemniscal con- 
nections in the American opossum, Didelphis mar- 
supialis virginiana. J. Comp. Neur. 146:95-118. 
Huber, G.C., and E.C. Crosby. 1926. On thalamic and 
tectal nuclei and fiber paths in the brain of the 
American alligator. J. Comp. Neur. 40:97—227. 
Jane, J.A., and D.M. Schroeder. 1971. A comparison 
of dorsal column nuclei and spinal afferents in the 
European hedgehog, Erinaceus europeaus. Exp. 
Neurol. 30:1-17. 
Johnson, J.I., W.I. Welker, and B.H. Pubols, Jr. 1968. 
Somatotopic organization of raccoon dorsal column 
nuclei. J. Comp. Neur. 132:1-44. 
Karten, H. 1963. Ascending pathways from the spinal 
cord in the pigeon Columba livia. Proc. 16th Int. 
Congr. Zool., Washington, D.C. 2:23. 
Mehler, W.R. 1957. The mammalian ‘pain tract’ in 
phylogeny. Anat. Rec. 127:332. 
Mehler, W.R. 1969. Some neurological species differ- 
ences — A posteriori. Ann. N.Y. Acad. Sci. 167: 
424-468. 
Mehler, W.R., M.E. Feferman, and W.J.H. Nauta. 
1960. Ascending axon degeneration following an- 
terolateral cordotomy: An experimental study in 
the monkey. Brain 38:718-750. 
Merest, D.K. 1967. Experimental study of the pro- 
jections of the nucleus of the tractus solitarius and 
the area postrema in the cat. J. Comp. Neur. 130: 
277-300. 
Pedersen, R.A. 1974. A comparative study of brain- 
stem afferents from the spinal cord in three genera 
of side-necked turtle, Podocnemis unifilis, Pelusios 
subniger, Pelomedusa subrufa. Ph.D. Thesis, 
Downstate Medical Center, State University of 
New York. 
Riss, W., R.A. Pedersen, J.S. Jakway, and C.B. Ware. 
1972. Levels of function and their representation 
in the vertebrate thalamus. Brain, Behav. Evol. 
6:26-41. 
Robards, M.J., D.W. Watkins, and R.B. Masterton. 
1974. Nucleus intercollicularis : Somesthetic tectum. 
Anat. Rec. 178:448. 
Rose, J.E., D.D. Greenwood, J.M. Goldberg, and J.E. 
Hind. 1963. Some discharge characteristics of 
single neurons in the inferior colliculus of the 
cat. I. Tonotopical organization, relation of spike- 
