48 THE LOWER PRIMATES 



(Trd) are still prominent, while the dorsal columns of Goll and Burdach 

 again give evidence that the more mesial of these fasciculi, representing the 

 leg and tail, is larger than the lateral one representing the upper extremity. 



FIG. 24. LEMUR MONGOZ. LEVEL THROUGH MIDDLE OF INFERIOR OLIVE. 



CB, Column of Burdach; do. Dorsal Accessory Olive; dt, Deiterso-spinal Tract; fle. Dorsal Spinocerebellar 

 Tract; cow. Ventral Spinocerebellar Tract; 10, Inferior Olive; mf. Mesial Fillet; nb. Nucleus of Burdach; 

 NBL, Nucleus of Blumenau; ng, Nucleus of Goll; nhv. Hypoglossal Nucleus; nr. Nucleus of Rolando; N12, 

 Hypoglossal Nerve; pd, Predorsal Bundle; pl, Posterior Longitudinal Fasciculus; py. Pyramid; ref. Reticu- 

 lar Formation; rst. Rubrospinal Tract; spt. Spinothalamic Tract; trd, Descending Trigeminal Tract; 

 vo, Ventromesial Accessory Olive. [Accession No. 147. Section 102. Actual Size, 11 X 5 mm.) 



LEVEL OF THE VESTIBULAR NUCLEI (FIG. 26) 



At the level of the vestibular nuclei some noteworthy changes have 

 occurred. They result primarily from the introduction of two additional 

 sensory systems. One of these additional elements in the sphere of sensation, 

 namely, the tuberculum acusticum (Tub) is related to the sense of hear- 

 ing; the other, connected with the function of balancing, is the vestibular 



