262 



O. LARSELL 



together anteroposteriorly, with upward displacement of cere- 

 bellar structures. 



As will be more fully indicated later, the eminence formed by 

 the corpus cerebelli contains a group of cells which appear to 

 represent the foreshadowing of the nucleus dentatus of higher 

 vertebrates. These cells are located in the anterior and ventral 

 portion of the eminence, just medial to the dorsoventral plane of 

 the anterior diverticulum. Because of the massive structures 

 surrounding it on all sides except posteriorly, the anterior end 

 of the fossa rhomboidea is greatly reduced in size, particularly in 

 the region of the corpus cerebelli. Lateral to the anterior di- 

 verticulum the cerebellar structure is less massive and is contin- 

 uous with the rhomboidal lip (fig. 3). 



ABBREVIATIONS 



ax., axone 



br.conj., brachium conjunctivum 



caud., caudad 



cb., cerebellum 



c.cb., corpus cerebelli 



ceph., cephalad 



com.cb., commissura cerebelli (myelin- 

 ated component) 



com.cb. I., commissura cerebelli later- 

 alis (unmyelinated component) 



d.a., diverticulum anterior of recessus 

 lateralis 



f.l.m. , fasciculus longitudinalis medialis 



gr.c, granule cell 



lal., lateral 



l.aur., lobus auricularis 



lm., lemniscus 



mes., mesencephalon 



mes.V, radix mesencephalica trigemini 



m.fi., moss fibers 



m.s.p., midsagittal plane 



n.III, nervus oculomotorius 



n.IV, nervus trochlearis 



n.V, nervus trigeminus 



n.VII + VIII, nervi facialis et acusti- 

 cus 



n.IX, nervus glossopharyngeus 



nuc.dent., nucleus dentatus 



nuc.mes.V, nucleus mesencephalica tri- 

 gemini 



Pur.c, Purkinje cell 



r.l., recessus lateralis 



r.P.c, reduced Purkinje cells 



r.VII l.l.d., radix lateralis facialis dor- 



salis 

 r.VII l.l.m., radix lateralis facialis me- 



dius 

 r.VII l.l.m' ., radix lateralis facialis ven- 



tromedius 

 r.VII l.l.v., radix lateralis facialis ven- 



tralis 

 r.VIII, radix nervi acustici 

 str.gr., stratum granulare 

 str.mol., stratum moleculare 

 str.Pur., stratum of Purkinje cells 

 t.f., terminal fibers 

 tr.a., dorsal longitudinal tract of area 



acustica 

 tr.b., ventral longitudinal tract of area 



acustica 

 tr.m.cb., tractus mammilloccrebellaris 

 tr.sp.cb.d., tractus spinocerebellars 



dorsalis 

 tr.sp.cb.v., tractus spinocerebellars 



ventralis 

 tr.sp.t., tractus spinotcctalis 

 tr.v.a., tractus visceralis ascendens 



(secondary gustatory tract) 

 v.m.a., velum medullare anterior 



