922 
and the art. cerebelli posterior inferior are of especial interest to us. 
They originate on both sides from a joint small branch of the art. 
vertebralis on the anterior side of the oblongata. The art. spinalis 
dorsalis then descends along the lateral surface of the oblongata and 
provides for the caudal portion of the medulla oblongata. The art. 
cerebelli ascends between’ the corp. restiformis and the oliva inferior, 
it provides for the laterodorsal portion of the m. oblongata in its 
proximal part by means of small branches originating from it in 
perpendicular direction, and then leaves the corpus restiforme to 
supply further with blood the distal half of the basal cerebellum- 
laminae. 
The area of irrigation of the art. cerebelli inferior posterior is 
accordingly situated within the latero-dorsal portion of the med. 
oblongata proximally to that of the art. spinalis dorsalis. 
The N. octavus is lying proximal to this irrigation-zone. 
The boundary line between pons and oblongata forms the proximal 
demarcation of this region, about there where the distal part of the 
nucleus N. VI is to be found. Caudally it is confined by the N. 
ambiguus, the caudal extremity of which is provided for by the 
art. spinalis dorsalis. The ventral boundary is indicated approximatively 
by the Oliva-nucleus; the dorsal one by the basal nuclei that have 
their own suppiy of arteries, the medial boundary by the nucleus 
and the roots of the N. XII. 
Surveying a topographical map of the meduila oblongata, we may 
see that within the irrigation zone of the art. cerebelli posterior inferior 
are found: 
Fig. Ill. Scheme of the area of irrigation of the 
art. cerebelli inferior hit by a frontal section. 
Trans por FHF 
< 
a. That part of the tractus spinalis N. V, that is going in a caudal 
