52 



Scientific Proceedings (56). 



cattle entirely free from tuberculous taint and yet endowed with 

 all the most valuable strain characteristics possessed by this 

 breed of stock. 



30 (847) 



The function of the otic labyrinth in turtles. 



By J. Gordon Wilson and F. H. Pike. 



[From the Department of Physiology, College of Physicians and 



Surgeons.] 



The peculiar method of progression in serpents 1 and the 

 widely different modes of progression in lizards, snakes and turtles 2 

 have attracted attention to the relation of the semi-circular canals 

 to the processes of progression and maintenance of equilibrium 

 in these forms. 



The general results of labyrinthine extirpation in all these 

 forms are similar to the results observed in other vertebrate 

 types. There is, in the turtle, torsion of the head to the injured 

 side, permanent deviation of the eyes and a tendency to crawl or 

 swim toward the injured side, when the lesion is unilateral. The 

 body on the uninjured side may be raised higher than on the 

 injured side. 



After bilateral operation, there are coarse wide tremors of the 

 head which seriously interfere with grasping food. The gait on 

 land is not markedly affected permanently, and there is no perma- 

 nent torsion of the head to either side. The head may, however, 

 be displaced directly upward and backwards in the first few days 

 following extirpation. Swimming is a matter of great difficulty. 

 When the turtle moves slowly, progress is fairly good, but agita- 

 tion or hurry upset coordination and extreme disorientation 

 results. The animal's reactions are not biologically adequate 

 (Edinger). 



It may be shown in turtles and snakes particularly that the 

 otic labyrinth is a great proprioceptive organ for the head segment 

 (Sherrington). The role of the labyrinth in the maintenance of 

 equilibrium rests primarily upon its relation to the head, and only 



1 Henri, Comples rendus de la Soc. de Biol., Paris, 1899, I, lie serie, 94-5. 



2 Trendelenburg and Kiihn, Archiv fiir Physiologic 1908, pp. 160. 



