166 PHYSIOLOGICAL SERIES. 



D. 199. Cast of the cranial cavity of a Tasmanian Devil (<V 

 jj/iflnn [M/,vy !////,<] H minus). [In duplicate.] 



This shows better than the actual specimen (which is 

 liable to distortion) the large proportions of tin- olfactory 

 l)iill)s and the relations of the cerebellum (the chief division* 

 of which are clearly seen) to the cerebral hemispheres, 



Note the orbital sulcus on the hemisphere (fig. 45) . 



P. Gervais, Nouv. Archiv. Mus., t. v. 1869, PI. xiv . ii . 



D. 200. A young Australian "Native Cat" (Dasyurus rir, ,- 

 rimes), with the brain and spinal cord exposed in situ. 



Parts of the hemispheres have been removed so as to 

 expose the hippocampi from above. 0. C. 1323 b. 



D. 201. The right half of the brain of an Australian "Native 

 Cat" (J)asyurus viverrinus), separated by a mesial sagittal 

 section. 



Two white bristles have been inserted into the hippo- 

 campal fissure just above the prominent fascia ilcntata 

 which rests upon the dorsal commissure. A black bristle 

 has been inserted just below the ventral (anterior) commis- 

 sure and another in the centre of the large " soft " or 

 " middle commissure " (so-called). The cavity of the third 

 ventricle in which the latter is placed may be clearly seen in 

 this speeimen. Its communication with the lateral ventricle, 

 viz., the foramen of Monro, may be distinctly seen in the 

 groove between the dorsal and soft commissures. 



Note the large size of the aqueduct of Sylvius, which 

 opens from the posterior extremity of the third ventricle 

 into the mid-brain. The roominess of this canal is very 

 suggestive when it is recalled that in most submammaliM 

 forms a ventricle exists in this situation and extends into 

 i In- " optic lobes." 



Note further the simplicity of the cerebellum. It- 

 deepest fissure the fissura prima opens on the anterior 

 surface near the apex of the organ : it is the homologue of 

 the proclival ii urn of Human Anatomy. 



All of these features (excepting the arrangement, of tin- 



hippOOampUfl ami the commissures) are common to other 

 lowly mammalian brains, such a> those of the ln>e<-i i\ora. 



O. C. 1323 c. 



