470 THE BRAIN OF MAMMALS, BY TH. MEYNERT. 



close looping of its nucleus dentatus, its highest development, so 

 that Schroder v. d. Kolk erroneously believed the superior and 

 inferior olivary bodies of Mammals to be fused into the lower 

 olive of Man. The so-called accessory olivary bodies (external 

 and internal) agree in being composed of finely granular grey 

 connecting substance and multi-caudate nerve corpuscles, hav- 

 ing a length of 24 ju, and a thickness of from 9 to 12 ju, and 

 perhaps constitute masses that are not actually separated from 

 the nucleus dentatus, but are only the external curved border 

 of its lamina, which opens posteriorly and internally in the 

 so-called hilus. The separation of these masses would then be 

 partially simulated by the abundant passage of transverse me- 

 dullary fasciculi. Reichert, from the macroscopic appearance of 

 the transverse section of the medulla oblongata, maintained the 

 view that the accessory olives are transverse sections of blood 

 coagula in small vessels that have assumed a grey tint in con- 

 sequence of the action of chromic acid. The inferior olivary 

 body is situated more anteriorly in regard to the longitudinal 

 fasciculi of the tegmentum than the superior, and is imbedded 

 in the middle of the medulla of the fillet (olivary column of 

 Burdach), the fasciculi of which, slightly curved inwards and 

 backwards, penetrate the nucleus dentatus in longitudinal 

 spiral lines, join with its cells, and constitute the longitudinal 

 portion of the medulla forming the contents of the olivary sacs. 

 I have completely satisfied myself of this from an examination 

 of Clason's beautiful longitudinal sections of the brain of the 

 Monkey. Deiters has also explained the olivary bodies as 

 being connected with the columns of the spinal cord. 



Owing to the conformation of the olivary bodies, such adjoining fas- 

 ciculi of the fillet as do not penetrate into their interior, but simply 

 cover them, project with a convex surface as " investing columns " 

 (" Hulsenstrange," Burdachs), whose relation to the olives being ex- 

 ternal, exceptional, and unessential, causes them to be subject to 

 variations in their number and size. 



In addition to these detached masses of grey matter, the 

 olives, and to the masses standing in evident connection with 

 the roots of the cerebral nerves, and which will be mentioned 

 further on as their nuclei, the posterior division of the pons 



