4 C. WINKLER. THE CENTRAL COURSE 



of the labyrinth , or on the section of the Nervus VIII , or on that 

 of the corpus trapezoides , or on that of the dorsal tract of the N. octa- 

 vus , have been controlled regularly and minutely by the degenerative 

 or atrophical changes, found after these operations in the central 

 organ , and demonstrated by means of the methods either of MARCHI , 

 of VON GUDDEN , of NISSL or of CAJAL, as may best fit the case. 

 Though the experiments of EVVALD deserve justly to be called 

 masterly, yet there remains an incertitude adhering to the results 

 they have produced. The anatomical control of his operations on 

 pigeon?, carried through in an admirable mariner for the periferical- 

 organs - - the end-organ of the eighth cerebral nerve - - was not 

 attempted for its mode of distribution in the central system. 



This is no imaginary objection. In some instances it becomes 

 very palpable. When f. i. EWALD , speaking about his experiments 

 on rabbits, writes: ,,Im ganzen eignen sich diese Tiere nicht sehr 

 gut zur Untersuchung der Labyrinthstorungen" the importance of 

 this objection becomes evident. 



The real meaning of this sentence is doubtless, that rabbits, 

 whose labyrinth has been removed , more especially if it has been 

 removed on one side, show certain symptoms (rollings round the 

 longitudinal axis , constraint-situation of the eyes) not shown plainly 

 in pigeons, whilst other symptoms, appearing beautifully in pigeons 

 (the progression of the paroxismally produced peculiar attitude of 

 head and neck , the atony of the extremities on one side) either are 

 shown differently, or else offer difficulties of demonstration in rabbits. 



It would be just as right however to maintain, that for the 

 same reason pigeons are animals less suited for experiments upon 

 the labyrinth than rabbits. 



Still both opinions would be inconsiderate. For the mode of 

 distribution of the nervus octavus in the central nerve-system is so 

 widely different in both species of animals, that we may not rea- 

 sonably expect a perfect conformity in the symptoms of both species, 

 when the labyrinth has been removed. 



The more to be admired therefore is the perspicacity of EWALD, who 

 apprehended how, in one respect, the functional loss , most conspicuous 

 after the destruction of the labyrinth, was found to be accordant. 



In demonstrating that a very serious atony of the extremities 

 especially on one side is caused by removal of one labyrinth, 

 EWALD has put a clue into the hands of anatomists , who know 

 very well that in despite of all differences , there still exists a great 

 conformity in the structure of the nervus octavus in the different 

 animal species. 



