164 PHYSIOLOGICAL SERIES. 



Thylacine (fig. 50). It is not possible to suggest any 

 limnology between this and a named sulcus of any other 

 mammalian brain. 



The neopallium in the Tasmanian Devil thus exhibits 

 1'ratiires of interest as a connecting link between the smooth 

 hemispheres of the smaller Dasyurids and the deeply 

 fissured hemispheres of the Thylacine, the sulcal pattern 

 of which it so clearly foreshadows. 



The base of the brain (compare with Perameles, fig. 52) 

 presents features which differ in a very marked manner 

 from those of the Monotreme brain, and closely agree with 

 the characters of the vast majority of other mammals. 

 Thus the pons presents the appearance of an almost 

 uniform transverse band and lacks the peculiar rostrum of 

 the Monotreme; moreover, the majority of its fibres pass 

 in front of the trigeminal nerve ; the pyramidal tracts 

 appear as prominent bands which decussate in a more or 

 less compact mass, and not as a diffuse crossing, a- in 

 the Monotremes : the trapezoid bodies, which are not 

 recognisable as such to the naked eye in the Platypus and 

 the Spiny Anteater, are now very prominent and well- 

 defined features. Each half of the trapezoid body consists 

 of a large strand of fibres which springs from the acoustic 

 tul>ercle (where the nerve-fibres from the cochlea end), 

 and, after pursuing a transverse course on the caudal side 

 of the pons. dips into the medulla and passes chiefly into 

 the lateral fillet of the opposite side. It constitutes the 

 chief cerebral path for auditory impulses. 



Tlio pituitary body ha> been torn away with the infun- 

 dibuliim, so that the mesial slit-like third ventricle has been 

 opened up between the largo optic chiasma and the 

 di.-tinrtly paired corpora mammillaria. In the depnion 

 behind the latter note the large interpeduncular body in 

 contact with the pons. 



The cerel>ellum conforms to a simple type sueli as ire 

 find in the In-eetivora. Uodentia. ( 'hiroptera, and l>a-y- 

 podidae (Edentata). Projecting upon each side there 

 lar^e irregular mass of folia resting upon the l.it'-ral aspect 

 of the pons and medulla oblongata, and separated from th< 



