140 Journal of Comparative Neurology. 



sis; Postpar. postparaphysis; Com. hab. commissure of the habena; Epiph. 

 epiphysis. 



Fig. 2. Portion of a section, somewhat farther ventrad, enlarged, showing 

 the two commissures of the habena. 



Fig. J. Meyn. B. Meynert's bundle; Plex, auliplexus; Post. c. postcom- 

 missure; Br. brachial tract. 



Fig. 4. Section still ventrad. 



^^S- 5- com. horiz. commissura horizontalis; Mes. n. v. mesencephalic 

 nidulus of the trigeminus; yf/«(5. fimbria. 



Fig. 6. Corp. forn. Corpus fornicis; Supra, tr. supraconimissure tract 

 passing to cerebrum; C. transv. commissura transversa; Lenin, lemniscus. 



Fig. 7. Section near ventral part of hippocampal lobe. 



Fig. 8. Cells from region of ventricle adjoining the nidulus niger. 



Fig. g. Corpus posterior (left side) in frog. The arrow indicates cephalic 

 direction. 



PLATE XX. 



Details of Histology of Reptiles and Amphibians. 



Fig. I. A portion of the hippocampal region of Necturus. Horizontal 

 section (5-i)» right hemisphere. The arrow indicates the direction of the 

 fornix commissure. 



Fig. 2. Olfactory cells from perpendicular section of olfactory tuber of 

 the frog. 



Fig. 3. Olfactory neuron and connection with glomerule [glom.) 



Fig. 4. Hippocampal region of frog from a perpendicular section {7-6). 



Fig. £, Mid-cortex region of frog from perpendicular section (4). 



Fig. 6. Perpendicular section of cerebellum of the turtle ( Cistiido). 



Fig. 7. Cells from a perpendicular section of cerebellum of frog 



Fig. 8. Similar cells from horizontal section showing dissimilarity of adja- 

 cent cells. Due probably to differential functioning. 



Fig. g. Longitudinal section of cerebellum of black snake (13). 



Fig. 10. Cells from the nidulus niger of frog. Arrow indicates ventral 

 direction. From a perpendicular section. 



Fig. ij. Cells of same region (3) Fig. a. 



Fig. 12. Cells from thalamic niduli of frog from which arise infracommis- 

 sure fibres. 



Fig. IJ. Cells from hippocampus of black snake (13-14. 



