Turner, Morphology of the Avian Brain. 379 



tion between the root of the auditory nerve and the longitu- 

 dinal fasciculus. 



Fasciculi of the Glosso-pharyngeal and Pncuniogastric 

 Nerves. — The fibres of these nerves pass directly entad to 

 their respective niduli. 



Fasciculi of the Spinal Accessory Nerve. — The internal 

 root of this nerve consists of a longitudinal series of fasciculi 

 which pass entad from the root to the nidulus of the spinal 

 accessory nerve. 



Fasciculus of the Hypoglossal Nerve. — This fasciculus 

 passes from its nidulus directly ventro-laterad to its external 

 root. 



Raphe. — The only commissure in this region is the com- 

 missure which connects the two halves of the metencephalon. 

 This commissure extends along almost the entire length of 

 the metencephalon, and is familiarly known as the raphe. 



Crossed Pyramidal Tract. — The course of this bundle is 

 the same in the avian brain as it is in the human. 



Direct Pyramidal Tract. — The course of this tract in the 

 avian brain is similar to the corresponding tract of the human. 

 But it is composed of a small fraction only of the median 

 longitudinal fibres that are found near the ventral surface of 

 the medulla. The remainder go to form the dorso-median 

 fasciculus. 



Direct Cerebellar Tract. — The homologue of this tract is 

 present and has a course similar to its course in the human 

 brain. 



Posterior I^ongitudinal P^asciculus (dorso-median fascicu- 

 lus). — Among anatomists the cephalad terminus of this 

 bundle has long been a open problem. During the past two 

 years two distinguished anatomists, Edinger(') and Honeg- 

 ger,(') have each oflered a solution of this problem. Each 



1 Dk. Ludwig Euingek, " Twelve Lectures on the Structure of the Central Nervous 

 System." Trans, by Willis Hall Vittum, M.D., p. 120. 



2 Jacob Honegger, " Vergleichende Anatomische Uutersuchung iiber den Fornix 

 und die zu ihm Beziehung Gebrachten Gebilde in Cehirns des jMenschen und der 

 Saiigethiere." 



