THE PIGEON. 261 



368. The relations of the anterior (a.c), posterior (p.c], 

 and optic (o.c) commissures. 



369. The arbor vitae, or foliated appearance produced 

 in the section of the cerebellum by the superficial grey 

 matter being continued inwards into the sulci, and investing 

 the outward prolongation of the central white matter into 

 the gyri. If a second brain is not at hand, this maybe seen 

 in a section of the cerebellum removed in LVI : it is best 

 seen, however, in a fresh brain. 



