192 
THOMPSON YATES LABORATORIES REPORT 
DESCRIPTION OF PLATES 
The figures have been drawn by one of us (R. B.) by means of Edinger's camera lucida, and 
are all of nearly equal magnification. 
Plate IV. Figs, i — 7 
Fig. I Pigeon. Horizontal section through cerebral hemisphere. Very superficial. Weigert stain. 
Left hemisphere. 
A. Pallial tract. Origin seen on mesial surface of section. 
Fig. 2 Pigeon. Horizontal section through cerebral hemisphere. Slightly deeper than Fig. i, and 
showing the ventricle. This and the succeeding sections are through the right 
hemisphere. 
A. Pallial tract, taking origin from the fore part of the brain, from the mesial surface, and 
extending laterally. 
Fig. 3 Pigeon. Horizontal section, deeper than preceding figures. 
J. Pallial tract, taking origin from fore part of brain and from the mesial and lateral 
aspect. 
Fig. 4 Pigeon. Horizontal section, at a deeper level than the preceding. 
A. Pallial tract. E. iff F. Origin of Tr. occipito-mesencephalicus and Tr. occipito- 
frontalis. 
Fig. 5 Pigeon. Horizontal section. Deeper level than preceding figures. 
A. Pallial tract. B. Origin of striothalamic tract. C. Origin of strio-mesencephalic 
tract. E. iff F. Origin of occipito-mesencephalic tract and occipito-frontal tract. 
F. Anterior fibres of occipito-frontal tract. 
Fig. 6 Pigeon. Horizontal section, at a deeper level than preceding figures. 
Letters as above. 
Fig. 7 Pigeon. Horizontal section, at a deeper level than preceding. Weigert stain. 
Letters as above, E. dff A.zv. Occipito-mesencephalic and anterior commissural fibres. 
Ti. Optic thalamus. Epithfr. Epithalamic fibres. Op.Ch. Optic chiasma. Op.md. 
Median optic bundle. Op. v. Optic vesicle. Lm.Cm.Ms. Lamina commissuralis 
mesencephali. 
Plate V. Figs. 8—14 
Fig. 8 Pigeon. Horizontal section, at a deeper level than preceding. Weigert stain. 
Letters as above. 01. Olfactory lobe. C.pl. Commissura anterior et posterior Palli. 
Op.tr. Optic tract. Tk.fb. Thalamic fibres. 
Fig. 9 Pigeon. Horizontal section through the base of brain. Weigert stain. 
Letters as above. Th. n. Thalamic nuclei, tr.fr. Transverse fibres of mesencephalon. 
IV. Fourth nerve. 
Fig. 10 Pigeon. Horizontal section, at a deeper level than preceding. Weigert stain. 
Letters as above, n.i.m. Thalamic nuclei. 
Fig. 1 1 Pigeon. Horizontal section through deeper plane than preceding. Weigert stain. 
Letters as above. Ax.C. Strio-mesencephalic and deep descending tracts. 7r.tect.sp. 
Tr. tecto-spinalis. 
Fig. I 2 Pigeon. Horizontal section through optic chiasma and optic vesicle. Weigert. 
Op.Ch. Optic chiasma. Gn. Corpus geniculatum. Gd. Gudden's commissure. C.p.c. 
Commissura post chiasmatica. Ax. Deep descending tracts. Diag. Diagonal tract. 
///. Third nerve. 
Fig 13 Pigeon. Horizontal section, deeper than preceding section, and showing optic tract and tracts 
in connection with it. 
Letters as above in fig. 12. lnf.tr. Tr. Infundibularis. 
Fig. 14 Pigeon. Horizontal section, deeper than figs. 12 and 13 ; showing optic chiasma and tracts in 
connection with it. 
Letters as in above. Dec.sup.inf. Decussatio supra-infundlbularis. G.Ect. Ganglion 
ectomammillare. 
