PYRAMID TRACT IN SQUIRREL AND CHIPMUNK 145 



Fig. 2 Transverse section of mesencephalon through anterior corpora quad- 

 rigernina. X 6 



Fig. 3 Transverse section, near junction of mid-brain and pons. X 6. 



Transverse section through junction of pons and medulla oblon- 

 gata (fig. 5). Sections passing through the seventh nucleus show 

 that the tract has now reached the surface and entered into the 

 formation of the anterior pyramid. Its transverse outhne at this 

 level is somewhat lens-shaped, the posterior surface being flat- 

 tened towards the inner angle and showing an increased curva- 

 ture towards the outer. The degeneration is abundant and is 



THE JOURNAL OF COMPARATIVE NECROLOGY, VOL. 24, NO. 



