28o F/SH. 



EXPLANATION OF PLATE XIIL 



Fig. I. The brain of Destnognathus fusca from the ventral aspect. X 20. 



Fig. 2. The same from the dorsal aspect. X 20. 



Fig. 3. A mesal section of the brain, reconstructed from sagittal sections. 

 X 20. 



Fig. 4. Sinistral aspect. X 20. 

 • Figs. 5-7. Frontal (horizontal) sections at different levels. The blue lines 

 represent the myelinic nerve-fibers, as shown by Weigert's hematoxylin stain. 

 The dark lines represent the amyelinic fiber-tracts. X 20. 



Fig. 8. A frontal section at the base of the brain, showing the arrangement of 

 the fibers at the chiasma, and the preoptic recess just cephalad ; also the thickening 

 of the caudal wall of the infundibulum where the hypophysis lies. X 20. 



Fig. 9. The most dorsal of the frontal sections, showing the origin of Mey- 

 nert's bundle and a portion of the postcommissure. X 20. 



Fig. id. A section at a little deeper level. It shows the relation of the para- 

 physis to the supraplexus, and of Meynert's bundle to the postcommissure. 

 X 20. 



