Mat 6, 1921] 



SCIENCE 



429 



do with the excitation. When the animal 

 was placed with its head 25 mm. from the 

 center of rotation it required no greater rate 

 of rotation to act as a stimulus than when 

 the head was 300 mm. from the center. The 

 centrifugal force in the latter position is 12 

 times as great as in the former, but the 

 angular velocity and hence tlie torsion effect 

 was the same in the two positions. 



Convection currents due to a difference in 

 temperature on the two sides of the vestibule 

 could much more conceivably occur in the 

 liquid of the vestibule tlian in the canals. 

 The nystagmus movements described by 

 Hogyes as a result' of irrigating the external 

 ear of man and many animals with hot or 

 cold water and the change of character of the 

 nystagmus by change of position of the head 

 can best be accounted for by the changes of 

 density of the liquid in the vestibule. The 

 reliability of Barany's use of these phenomena 

 for diagnostic purposes is not affected by the 

 acceptance of this view, but only his unscien- 

 tific explanation must be abandoned. 



I wish in closing to draw attention to the 

 fact that a survey of all the experimental 

 work on the labyrinth leads to the conclusion 

 that the stimulation of the vestibular struc- 

 tures and of the sensory endings in the 

 ampullae depend upon the same principle, 

 namely the effects of changes of relative ten- 

 sions. How the change of tension excites 

 the nerve endings and what part if any the 

 hair cells play in the process still remains 

 wholly outside the field of exi)erimental in- 

 vestigation. 



S. S. Maxwell 



UNIVERSiry OP CAilPORNIA 



EEFEKENCES 



Breuer, J. 



1899. TJeber die Bogeugansampullen. Zen- 

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1907-8. The labyrintlis of animals. London, J. 

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 Kubo, Ino. 



1906. TJeber die vom N. acusticus ausgelosten. 

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Lee, Frederic S. 



1893. A study of the sense of equiMbrium in 

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1891. TJeber Geotropismus bei Thieren. Arch, 

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1910. Experiments on the functions of the in- 

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1912. On the exciting cause of comipensatory 

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1919. Labyrinth and Equilibrium. I. A com- 

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1920o. Labyrinth and Equilibrium. II. The 

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19206. Labyriath and Equilibrium. III. The 

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1909. Influence of the eyes, ears and other allied 

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MEETING OF THE GENETICISTS 

 INTERESTED IN AGRICULTURE 



In conjunction with the meetings of the 

 American Association for the Advancement 

 of Science and affiliated societies in Chicago 

 an informal gatliering of instructors and in- 

 vestigators of genetics related to agriculture 

 was held December 28th at the University 

 of Chicago. Some thirty-five representatives 

 from ficfteen Agricultural Colleges and Ex- 

 periment Stations, the United States Depart- 

 ment of Agriculture and other institutions 

 were present. Unfortunately the impossibility 

 of getting the final notices out until very late 

 prevented a number of others from attending. 

 The purpose of the meeting was to discuss 

 such topics of mutual interest at this time as 



