222 MARINE BIOLOGICAL LABORATORY. 



followed by loss of the ability to equilibrate the 

 body. 



An extended presentation of the arguments for and 

 against the equilibration theory of the semicircular 

 canals would be too long and unprofitable to justify 

 introducing it here, especially so now that there is no 

 longer the slightest evidence in favor of the theory, 

 since the results of experiments by the physiologist 

 Steiner have been published. It is commonly stated 

 that the auditory nerve, besides possessing the func- 

 tion of transmitting auditory impressions, also transmits 

 stimuli to the equilibrious centre, and that the ampullae 

 of the semicircular canals contain the sense-organs 

 which subserve this function. 



The ampullar sense-organs may, however, be com- 

 pletely severed from their respective nerves without 

 producing any disturbance in the equipoise of the 

 body. The section of the ampullar nerves, even though 

 the greatest care be taken to prevent damage to the 

 connecting nerves, must produce an intense stimulation 

 of the central end cells, and it is wholly unexplained 

 why the ampullar nerves may be thus cut without pro- 

 ducing any visible effect if the equilibration theory 

 were true. 



Experiments carried out in Hermann's laboratory in 

 1877, by Fraulein Tomaszewicz, showed that in bony 

 fishes the semicircular canals and their ampuUary sense- 

 organs could be entirely removed without in the least 

 influencing the equilibration of the body. Another set 

 of experiments, even more decisive, were performed 

 by Professor Steiner in 1888, in the physiological 

 department of the Naples zoological station, on the 



