Chapter IH. 



On the central distribution of the root-fibres 

 of the nervus octavus in pigeons. 



The central distribution of the rootfibres of the VIII th nerve in 

 pigeons differs in many respects considerably from that^ which in 

 the preceeding chapter has been described in rabbits. 



Therefore a comparison between the central system of the nervus 

 octavus in these two species of animals is not very easy. It may 

 even be called impossible, whithout homologizing the different 

 fasciculi and nuclei, participating to the formation of this extensive 

 system. And every attempt to homologize the octavus-nuclei of a 

 bird with those of a mammalian will be proved a more or less 

 subjective proceeding. It only may be tried, when a very minute 

 knowledge of the central course of the rootfibres has been acquired. 



My views upon the central distribution of the rootfibres in 

 pigeons are based chiefly upon the examination of series of sections 

 through their cerebrum, treated with MARcm-method within a 

 fortnight or three weeks after the removal of their labyrinth. 



Those series were made in frontal, horizontal and sagittal direction. 



The removal of the labyrinth was executed by strictly following 

 the indications for this operation given by EWALD. As soon as the 

 operated pigeon begins to turn its head the in III th position 

 generally after a fortnight the animal is killed. 



Now it must be observed, that in pigeons, the results of the 

 MARcm-method are often less sharply defined, as they usually are 

 in rabbits. I believe that the rather high temperature of the blood 

 in birds, may serve to explain the fact, that black globules are 

 very often found every-where and in places, where they never might 



